Time to Stable

For a given set of browsers, what APIs are in all of them and how many days it take for the API to land in the first browser to the last.

Example Comparisons
Browsers
Features

Summary

A count of the number of APIs that landed in A first and B last.
Last in ChromeLast in Edge
First in Chrome 364
First in Edge 9

Average time for an API to become available across Chrome and Edge

373 APIs took an average of 834.41 days to become available to use.

API breakdown:

Average time to landing by year of first landing

If a feature landed in the earliest browser in 20XX it took Y days on average to become available in the last browser (when considering Chrome and Edge). TTA (time to available).
HTTP APIsHTTP TTA
2008 642624.88
2010 162105.44
2011 51324.00
2012 21922.00
2013 151366.27
2014 2742.00
2015 191347.68
2016 10881.00
2017 28866.75
2018 24626.04
2019 17144.29
2020 1537.93
2021 532.23
2022 292.52
2023 332.73
2024 192.21
2025 212.43
2026 18.00

The Tortoise and the Hare

There is a natural tension on the web with respect to browser engines. Every engine has their own set of priorities which define the level of investment that they choose to make and on which areas they choose to make it.

A developer naturally wants their experiences to be available to the widest audience possible and these differing priorities create an unevenness on the platform (a lumpiness) making it harder for developers to build experiences that work everywhere.

This section highlights where browsers are pushing and pulling on the platform.

Sprinters

This table is designed to show which browsers are pushing on the platform the most.

Adding features to quickly is not always desired because developers are unlikely to adopt those features in their sites or apps.

For a given year, if a feature landed in Browser X first, how many days it take on average to be available in Chrome and Edge. TTA (time to available).
Year HTTPHTTP TTA
2008
  Chrome 642624.88
2010
  Chrome 162105.44
2011
  Chrome 51324.00
2012
  Chrome 21922.00
2013
  Chrome 151366.27
2014
  Chrome 2742.00
2015
  Chrome 181372.06
  Edge 1909.00
2016
  Chrome 10881.00
2017
  Chrome 27890.56
  Edge 1224.00
2018
  Chrome 24626.04
2019
  Chrome 17144.29
2020
  Chrome 1051.40
  Edge 511.00
2021
  Chrome 532.23
2022
  Chrome 272.63
  Edge 21.00
2023
  Chrome 332.73
2024
  Chrome 192.21
2025
  Chrome 212.43
2026
  Chrome 18.00

Plodders

This table is designed to show which browsers are pulling on the platform the most.

For a feature that first landed in year X, how many days did it take on average for the last browser to catch up across Chrome and Edge. TTA (time to available).
Year HTTP countHTTP TTA
2008
  Edge 642624.88
2010
  Edge 162105.44
2011
  Edge 51324.00
2012
  Edge 21922.00
2013
  Edge 151366.27
2014
  Edge 2742.00
2015
  Edge 181372.06
  Chrome 1909.00
2016
  Edge 10881.00
2017
  Edge 27890.56
  Chrome 1224.00
2018
  Edge 24626.04
2019
  Edge 17144.29
2020
  Edge 1051.40
  Chrome 511.00
2021
  Edge 532.23
2022
  Edge 272.63
  Chrome 21.00
2023
  Edge 332.73
2024
  Edge 192.21
2025
  Edge 212.43
2026
  Edge 18.00

Stable APIs

Below is a list of features that are in Chrome and Edge

Raw Data

Quick Links:

HTTP Data

API First Browser Date Last Browser Date Days Notes
http.data-url 📋Chrome1/25/2010 Edge7/29/20152011
Edge: Before Edge 79, the maximum size supported is 4GB.Internet Explorer: Since Internet Explorer 9, the maximum size supported is 4GB.Internet Explorer: In Internet Explorer 8, the maximum size supported is 32kB.
http.data-url.css_files Chrome1/25/2010 Edge7/29/20152011
http.data-url.html_files Chrome1/25/2010 Edge1/15/20203642
http.data-url.js_files Chrome1/25/2010 Edge7/29/20152011
http.data-url.top_level_navigation_blocked Chrome7/25/2017 Edge1/15/2020904
http.headers.Accept 📋Chrome12/11/2008 Edge7/29/20152421
Firefox: In Firefox 66, the default Accept header value changed to */*.Firefox for Android: In Firefox for Android 66, the default Accept header value changed to */*.
http.headers.Accept-CH 📋Chrome10/13/2015 Edge1/15/20201555
http.headers.Accept-CH.Content-DPR Chrome10/13/2015 Edge1/15/20201555
http.headers.Accept-CH.DPR Chrome10/13/2015 Edge1/15/20201555
http.headers.Accept-CH.Device-Memory Chrome9/5/2017 Edge1/15/2020862
http.headers.Accept-CH.Sec-CH-DPR 📋Chrome1/4/2022 Edge1/6/20222
http.headers.Accept-CH.Sec-CH-Device-Memory 📋Chrome1/4/2022 Edge1/6/20222
http.headers.Accept-CH.Sec-CH-UA Chrome3/2/2021 Edge3/4/20212
http.headers.Accept-CH.Sec-CH-UA-Arch Chrome3/2/2021 Edge3/4/20212
http.headers.Accept-CH.Sec-CH-UA-Full-Version Chrome3/2/2021 Edge3/4/20212
http.headers.Accept-CH.Sec-CH-UA-Mobile Chrome3/2/2021 Edge3/4/20212
http.headers.Accept-CH.Sec-CH-UA-Model Chrome3/2/2021 Edge3/4/20212
http.headers.Accept-CH.Sec-CH-UA-Platform Chrome3/2/2021 Edge3/4/20212
http.headers.Accept-CH.Sec-CH-UA-Platform-Version Chrome3/2/2021 Edge3/4/20212
http.headers.Accept-CH.Sec-CH-Viewport-Height 📋Edge9/1/2022 Chrome9/2/20221
http.headers.Accept-CH.Sec-CH-Viewport-Width 📋Chrome1/4/2022 Edge1/6/20222
http.headers.Accept-CH.Sec-CH-Width 📋Chrome1/4/2022 Edge1/6/20222
http.headers.Accept-CH.Viewport-Width Chrome10/13/2015 Edge1/15/20201555
http.headers.Accept-CH.Width Chrome10/13/2015 Edge1/15/20201555
http.headers.Accept-Encoding 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Accept-Encoding.br 📋Chrome4/13/2016 Edge4/5/2017357
Safari: Unsupported before macOS 10.13 High Sierra.
http.headers.Accept-Encoding.dcb Chrome10/15/2024 Edge10/17/20242
http.headers.Accept-Encoding.dcz Chrome10/15/2024 Edge10/17/20242
http.headers.Accept-Encoding.zstd 📋Chrome3/19/2024 Edge3/22/20243
Safari: Before macOS 26.3 Tahoe, this header value is not sent.
http.headers.Accept-Language 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Accept-Ranges 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Access-Control-Allow-Credentials 📋Chrome1/25/2010 Edge7/29/20152011
http.headers.Access-Control-Allow-Headers 📋Chrome1/25/2010 Edge7/29/20152011
http.headers.Access-Control-Allow-Headers.wildcard Chrome12/6/2017 Edge1/15/2020770
http.headers.Access-Control-Allow-Methods 📋Chrome1/25/2010 Edge7/29/20152011
http.headers.Access-Control-Allow-Methods.wildcard Chrome12/6/2017 Edge1/15/2020770
http.headers.Access-Control-Allow-Origin 📋Chrome1/25/2010 Edge7/29/20152011
http.headers.Access-Control-Expose-Headers 📋Chrome1/25/2010 Edge7/29/20152011
http.headers.Access-Control-Expose-Headers.wildcard Chrome3/6/2018 Edge1/15/2020680
http.headers.Access-Control-Max-Age 📋Chrome1/25/2010 Edge7/29/20152011
http.headers.Access-Control-Request-Headers 📋Chrome1/25/2010 Edge7/29/20152011
http.headers.Access-Control-Request-Method 📋Chrome1/25/2010 Edge7/29/20152011
http.headers.Activate-Storage-Access 📋Chrome2/4/2025 Edge2/6/20252
http.headers.Age 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Alt-Svc 📋Chrome7/20/2016 Edge1/15/20201274
Firefox: Only supports draft-04Firefox for Android: Only supports draft-04
http.headers.Attribution-Reporting-Eligible 📋Chrome9/12/2023 Edge9/15/20233
http.headers.Attribution-Reporting-Register-Source 📋Chrome9/12/2023 Edge9/15/20233
http.headers.Attribution-Reporting-Register-Trigger 📋Chrome9/12/2023 Edge9/15/20233
http.headers.Attribution-Reporting-Support 📋Chrome9/12/2023 Edge9/15/20233
http.headers.Authorization 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Authorization.Basic 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Authorization.Digest 📋Chrome12/11/2008 Edge1/15/20204052
http.headers.Authorization.Digest.SHA-256 Chrome9/12/2023 Edge9/15/20233
http.headers.Authorization.Digest.md5 Chrome12/11/2008 Edge1/15/20204052
http.headers.Authorization.NTLM Chrome12/11/2008 Edge1/15/20204052
http.headers.Authorization.Negotiate 📋Chrome12/11/2008 Edge1/15/20204052
http.headers.Available-Dictionary 📋Chrome10/15/2024 Edge10/17/20242
http.headers.Cache-Control 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Cache-Control.stale-while-revalidate 📋Chrome6/4/2019 Edge1/15/2020225
http.headers.Clear-Site-Data 📋Chrome9/5/2017 Edge1/15/2020862
http.headers.Clear-Site-Data.cache 📋Chrome3/6/2018 Edge1/15/2020680
Chrome: Setting this value may increase response duration (see bug 40233601.Chrome: Setting this value may prevent a page from fully load (see bug 41343050.Chrome Android: Setting this value may increase response duration (see bug 40233601.Chrome Android: Setting this value may prevent a page from fully load (see bug 41343050.Edge: Setting this value may increase response duration (see bug 40233601.Quest Browser: Setting this value may increase response duration (see bug 40233601.Opera: Setting this value may increase response duration (see bug 40233601.Opera: Setting this value may prevent a page from fully load (see bug 41343050.Opera Android: Setting this value may increase response duration (see bug 40233601.Opera Android: Setting this value may prevent a page from fully load (see bug 41343050.Samsung Internet: Setting this value may increase response duration (see bug 40233601.WebView Android: Setting this value may increase response duration (see bug 40233601.WebView Android: Setting this value may prevent a page from fully load (see bug 41343050.
http.headers.Clear-Site-Data.clientHints 📋Chrome9/12/2023 Edge9/15/20233
http.headers.Clear-Site-Data.cookies 📋Chrome9/5/2017 Edge1/15/2020862
http.headers.Clear-Site-Data.prefetchCache Chrome6/24/2025 Edge6/26/20252
http.headers.Clear-Site-Data.prerenderCache Chrome6/24/2025 Edge6/26/20252
http.headers.Clear-Site-Data.secure_context_required Chrome9/5/2017 Edge1/15/2020862
http.headers.Clear-Site-Data.storage 📋Chrome9/5/2017 Edge1/15/2020862
http.headers.Clear-Site-Data.wildcard 📋Chrome9/12/2023 Edge9/15/20233
http.headers.Connection 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Content-DPR Chrome10/13/2015 Edge1/15/20201555
http.headers.Content-Disposition 📋Chrome12/11/2008 Edge7/29/20152421
Chrome: When saving documents, the document title is used instead of the filename parameter if the disposition type is inline. See bug 352093465.Chrome Android: When saving documents, the document title is used instead of the filename parameter if the disposition type is inline. See bug 352093465.Firefox: From version 82, if an <a> element's download attribute is set (for a same-origin URL) then the inline directive is ignored. Earlier versions did not match the specification and respected the header directive over the attribute. See bug 1658877.Firefox for Android: From version 82, if an <a> element's download attribute is set (for a same-origin URL) then the inline directive is ignored. Earlier versions did not match the specification and respected the header directive over the attribute. See bug 1658877.Quest Browser: When saving documents, the document title is used instead of the filename parameter if the disposition type is inline. See bug 352093465.Opera: When saving documents, the document title is used instead of the filename parameter if the disposition type is inline. See bug 352093465.Opera Android: When saving documents, the document title is used instead of the filename parameter if the disposition type is inline. See bug 352093465.Safari: When saving documents, the document title is used instead of the filename parameter if the disposition type is inline. See bug 18384.Safari on iOS: When saving documents, the document title is used instead of the filename parameter if the disposition type is inline. See bug 18384.Samsung Internet: When saving documents, the document title is used instead of the filename parameter if the disposition type is inline. See bug 352093465.WebView Android: When saving documents, the document title is used instead of the filename parameter if the disposition type is inline. See bug 352093465.WebView on iOS: When saving documents, the document title is used instead of the filename parameter if the disposition type is inline. See bug 18384.
http.headers.Content-Encoding 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Content-Encoding.br 📋Chrome4/13/2016 Edge4/5/2017357
Safari: Unsupported before macOS 10.13 High Sierra.
http.headers.Content-Encoding.dcb Chrome10/15/2024 Edge10/17/20242
http.headers.Content-Encoding.dcz Chrome10/15/2024 Edge10/17/20242
http.headers.Content-Encoding.zstd 📋Chrome3/19/2024 Edge3/22/20243
Safari: Before macOS 26.3 Tahoe, Safari cannot decode Zstandard responses.
http.headers.Content-Language 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Content-Length 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Content-Length.cors_response_safelist Chrome7/30/2019 Edge1/15/2020169
http.headers.Content-Location 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Content-Range 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Content-Security-Policy 📋Chrome2/21/2013 Edge8/2/20161258
Internet Explorer: Only supporting 'sandbox' directive.
http.headers.Content-Security-Policy.base-uri 📋Chrome1/21/2015 Edge1/15/20201820
http.headers.Content-Security-Policy.block-all-mixed-content Chrome7/21/2015 Edge1/15/20201639
Chrome: Will be removed, see bug 40260100.Chrome Android: Will be removed, see bug 40260100.Edge: Will be removed, see bug 40260100.Quest Browser: Will be removed, see bug 40260100.Opera: Will be removed, see bug 40260100.Opera Android: Will be removed, see bug 40260100.Samsung Internet: Will be removed, see bug 40260100.WebView Android: Will be removed, see bug 40260100.
http.headers.Content-Security-Policy.child-src 📋Chrome1/21/2015 Edge4/5/2017805
http.headers.Content-Security-Policy.connect-src 📋Chrome2/21/2013 Edge8/2/20161258
Firefox: Before Firefox 50, ping attributes of <a> elements weren't covered by connect-src.
http.headers.Content-Security-Policy.default-src 📋Chrome2/21/2013 Edge8/2/20161258
http.headers.Content-Security-Policy.fenced-frame-src 📋Chrome6/11/2024 Edge6/13/20242
http.headers.Content-Security-Policy.font-src 📋Chrome2/21/2013 Edge8/2/20161258
http.headers.Content-Security-Policy.form-action 📋Chrome1/21/2015 Edge4/5/2017805
http.headers.Content-Security-Policy.form-action.blocks_redirects Chrome12/6/2017 Edge1/15/2020770
http.headers.Content-Security-Policy.frame-ancestors 📋Chrome1/21/2015 Edge4/5/2017805
Firefox: Before Firefox 58, frame-ancestors is ignored in Content-Security-Policy-Report-Only.Firefox for Android: Before Firefox for Android 58, frame-ancestors is ignored in Content-Security-Policy-Report-Only.
http.headers.Content-Security-Policy.frame-src 📋Chrome2/21/2013 Edge8/2/20161258
http.headers.Content-Security-Policy.img-src 📋Chrome2/21/2013 Edge8/2/20161258
http.headers.Content-Security-Policy.manifest-src 📋Chrome1/21/2015 Edge1/15/20201820
http.headers.Content-Security-Policy.media-src 📋Chrome2/21/2013 Edge8/2/20161258
http.headers.Content-Security-Policy.meta-element-support Chrome2/21/2013 Edge10/2/20182049
http.headers.Content-Security-Policy.object-src 📋Chrome2/21/2013 Edge8/2/20161258
http.headers.Content-Security-Policy.report-sample Chrome6/5/2017 Edge1/15/2020954
http.headers.Content-Security-Policy.report-to 📋Chrome10/16/2018 Edge1/15/2020456
http.headers.Content-Security-Policy.report-uri 📋Chrome2/21/2013 Edge8/2/20161258
http.headers.Content-Security-Policy.require-trusted-types-for 📋Chrome5/19/2020 Edge5/21/20202
http.headers.Content-Security-Policy.sandbox 📋Chrome2/21/2013 Edge8/2/20161258
http.headers.Content-Security-Policy.script-src 📋Chrome2/21/2013 Edge8/2/20161258
http.headers.Content-Security-Policy.script-src.external_scripts 📋Chrome6/5/2017 Edge1/15/2020954
http.headers.Content-Security-Policy.script-src.inline-speculation-rules Chrome2/7/2023 Edge2/9/20232
http.headers.Content-Security-Policy.script-src.wasm-unsafe-eval Chrome1/4/2022 Edge1/6/20222
http.headers.Content-Security-Policy.script-src-attr 📋Chrome6/4/2019 Edge1/15/2020225
http.headers.Content-Security-Policy.script-src-elem 📋Chrome6/4/2019 Edge1/15/2020225
http.headers.Content-Security-Policy.strict-dynamic Chrome7/20/2016 Edge1/15/20201274
http.headers.Content-Security-Policy.style-src 📋Chrome2/21/2013 Edge8/2/20161258
http.headers.Content-Security-Policy.style-src-attr 📋Chrome6/4/2019 Edge1/15/2020225
http.headers.Content-Security-Policy.style-src-elem 📋Chrome6/4/2019 Edge1/15/2020225
Safari: The style-src-elem directive was parsed, but had no effect. See bug 276931.Safari on iOS: The style-src-elem directive was parsed, but had no effect. See bug 276931.WebView on iOS: The style-src-elem directive was parsed, but had no effect. See bug 276931.
http.headers.Content-Security-Policy.trusted-types 📋Chrome5/19/2020 Edge5/21/20202
http.headers.Content-Security-Policy.unsafe-hashes Chrome9/4/2018 Edge1/15/2020498
http.headers.Content-Security-Policy.upgrade-insecure-requests 📋Chrome5/19/2015 Edge4/30/20181077
http.headers.Content-Security-Policy.worker-src 📋Chrome6/5/2017 Edge1/15/2020954
Chrome: Chrome 59 and higher skips the deprecated child-src directive.Chrome Android: Chrome Android 59 and higher skips the deprecated child-src directive.Quest Browser: Quest Browser 5.0 and higher skips the deprecated child-src directive.Opera: Opera 46 and higher skips the deprecated child-src directive.Opera Android: Opera Android 43 and higher skips the deprecated child-src directive.WebView Android: WebView Android 59 and higher skips the deprecated child-src directive.
http.headers.Content-Security-Policy.worker_support Chrome1/25/2017 Edge1/15/20201085
http.headers.Content-Security-Policy-Report-Only 📋Chrome2/21/2013 Edge8/2/20161258
http.headers.Content-Type 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Cookie 📋Chrome12/11/2008 Edge7/29/20152421
Safari: Cookies with Secure flag are not sent to unsecured http://localhost/ endpoints. See bug 281149.Safari on iOS: Cookies with Secure flag are not sent to unsecured http://localhost/ endpoints. See bug 281149.WebView on iOS: Cookies with Secure flag are not sent to unsecured http://localhost/ endpoints. See bug 281149.
http.headers.Critical-CH 📋Chrome5/25/2021 Edge5/27/20212
http.headers.Cross-Origin-Embedder-Policy 📋Chrome5/19/2020 Edge5/21/20202
http.headers.Cross-Origin-Embedder-Policy.credentialless 📋Chrome11/15/2021 Edge11/19/20214
http.headers.Cross-Origin-Embedder-Policy.report-to_parameter 📋Chrome11/15/2021 Edge11/19/20214
http.headers.Cross-Origin-Opener-Policy 📋Chrome5/19/2020 Edge5/21/20202
http.headers.Cross-Origin-Opener-Policy.noopener-allow-popups 📋Chrome11/12/2024 Edge11/14/20242
http.headers.Cross-Origin-Opener-Policy.report-to_parameter 📋Chrome11/15/2021 Edge11/19/20214
http.headers.Cross-Origin-Resource-Policy 📋Chrome3/12/2019 Edge1/15/2020309
Chrome: Until version 75, downloads for files with this header would fail in Chrome. See bug 41452948.Chrome: From version 80 to 85, linearized PDFs served inline with this header fail to render properly. See bug 40127935. From version 86, partial PDF loading is disabled.Chrome Android: Until version 75, downloads for files with this header would fail in Chrome Android. See bug 41452948.Chrome Android: From version 80 to 85, linearized PDFs served inline with this header fail to render properly. See bug 40127935. From version 86, partial PDF loading is disabled.Quest Browser: Until version 7.0, downloads for files with this header would fail in Quest Browser. See bug 41452948.Quest Browser: From version 9.0 to 85, linearized PDFs served inline with this header fail to render properly. See bug 40127935. From version 12.0, partial PDF loading is disabled.Opera: Until version 62, downloads for files with this header would fail in Opera. See bug 41452948.Opera: From version 67 to 85, linearized PDFs served inline with this header fail to render properly. See bug 40127935. From version 72, partial PDF loading is disabled.Opera Android: Until version 54, downloads for files with this header would fail in Opera Android. See bug 41452948.Opera Android: From version 57 to 85, linearized PDFs served inline with this header fail to render properly. See bug 40127935. From version 61, partial PDF loading is disabled.WebView Android: Until version 75, downloads for files with this header would fail in WebView Android. See bug 41452948.WebView Android: From version 80 to 85, linearized PDFs served inline with this header fail to render properly. See bug 40127935. From version 86, partial PDF loading is disabled.
http.headers.DNT Chrome11/6/2012 Edge7/29/2015995
http.headers.DPR Chrome10/13/2015 Edge1/15/20201555
http.headers.Date 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Device-Memory Chrome9/5/2017 Edge1/15/2020862
Chrome: From Chrome 147, reported values are 2, 4, 8, 16, and 32.Chrome: Before Chrome 147, reported values were 0.25, 0.5, 1, 2, 4, and 8.Chrome Android: From Chrome 147, reported values are 1, 2, 4, and 8.Chrome Android: Before Chrome 147, reported values were 0.25, 0.5, 1, 2, 4, and 8.Edge: From Edge 147, reported values are 2, 4, 8, 16, and 32.Edge: Before Edge 147, reported values were 0.25, 0.5, 1, 2, 4, and 8.Quest Browser: From Chrome 147, reported values are 1, 2, 4, and 8.Quest Browser: Before Chrome 147, reported values were 0.25, 0.5, 1, 2, 4, and 8.Opera: From Opera false, reported values are 2, 4, 8, 16, and 32.Opera: Before Opera false, reported values were 0.25, 0.5, 1, 2, 4, and 8.Opera Android: From Chrome 147, reported values are 1, 2, 4, and 8.Opera Android: Before Chrome 147, reported values were 0.25, 0.5, 1, 2, 4, and 8.Samsung Internet: From Chrome 147, reported values are 1, 2, 4, and 8.Samsung Internet: Before Chrome 147, reported values were 0.25, 0.5, 1, 2, 4, and 8.WebView Android: From Chrome 147, reported values are 1, 2, 4, and 8.WebView Android: Before Chrome 147, reported values were 0.25, 0.5, 1, 2, 4, and 8.
http.headers.Dictionary-ID 📋Chrome10/15/2024 Edge10/17/20242
http.headers.Downlink 📋Chrome5/29/2018 Edge1/15/2020596
Chrome: The value is never greater than 10 Mbps, as a non-standard anti-fingerprinting measure.Chrome Android: The value is never greater than 10 Mbps, as a non-standard anti-fingerprinting measure.Edge: The value is never greater than 10 Mbps, as a non-standard anti-fingerprinting measure.Quest Browser: The value is never greater than 10 Mbps, as a non-standard anti-fingerprinting measure.Opera: The value is never greater than 10 Mbps, as a non-standard anti-fingerprinting measure.Opera Android: The value is never greater than 10 Mbps, as a non-standard anti-fingerprinting measure.Samsung Internet: The value is never greater than 10 Mbps, as a non-standard anti-fingerprinting measure.WebView Android: The value is never greater than 10 Mbps, as a non-standard anti-fingerprinting measure.
http.headers.ECT 📋Chrome5/29/2018 Edge1/15/2020596
http.headers.ETag 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Expires 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Feature-Policy Chrome7/25/2017 Edge1/15/2020904
http.headers.Feature-Policy.accelerometer 📋Chrome4/17/2018 Edge1/15/2020638
http.headers.Feature-Policy.ambient-light-sensor 📋Chrome4/17/2018 Edge1/15/2020638
http.headers.Feature-Policy.attribution-reporting 📋Chrome9/12/2023 Edge9/15/20233
http.headers.Feature-Policy.autoplay 📋Chrome1/23/2018 Edge1/15/2020722
http.headers.Feature-Policy.bluetooth 📋Chrome8/2/2022 Edge8/5/20223
http.headers.Feature-Policy.browsing-topics Chrome7/18/2023 Edge7/21/20233
http.headers.Feature-Policy.camera 📋Chrome1/23/2018 Edge1/15/2020722
http.headers.Feature-Policy.compute-pressure 📋Chrome5/14/2024 Edge5/17/20243
http.headers.Feature-Policy.cross-origin-isolated 📋Chrome11/17/2020 Edge11/19/20202
http.headers.Feature-Policy.deferred-fetch 📋Chrome4/1/2025 Edge4/4/20253
http.headers.Feature-Policy.deferred-fetch-minimal 📋Chrome4/1/2025 Edge4/4/20253
http.headers.Feature-Policy.display-capture 📋Chrome9/21/2021 Edge9/24/20213
http.headers.Feature-Policy.document-domain 📋Chrome1/23/2018 Edge1/15/2020722
http.headers.Feature-Policy.encrypted-media 📋Chrome1/23/2018 Edge1/15/2020722
http.headers.Feature-Policy.fullscreen 📋Chrome10/17/2017 Edge1/15/2020820
http.headers.Feature-Policy.geolocation 📋Chrome1/23/2018 Edge1/15/2020722
http.headers.Feature-Policy.gyroscope 📋Chrome4/17/2018 Edge1/15/2020638
http.headers.Feature-Policy.hid 📋Chrome3/2/2021 Edge3/4/20212
http.headers.Feature-Policy.identity-credentials-get 📋Chrome2/7/2023 Edge2/9/20232
http.headers.Feature-Policy.idle-detection 📋Chrome9/21/2021 Edge9/24/20213
http.headers.Feature-Policy.local-fonts 📋Chrome6/21/2022 Edge6/23/20222
http.headers.Feature-Policy.magnetometer 📋Chrome4/17/2018 Edge1/15/2020638
http.headers.Feature-Policy.microphone 📋Chrome1/23/2018 Edge1/15/2020722
http.headers.Feature-Policy.midi 📋Chrome1/23/2018 Edge1/15/2020722
http.headers.Feature-Policy.otp-credentials 📋Chrome8/31/2021 Edge9/2/20212
http.headers.Feature-Policy.payment 📋Chrome7/25/2017 Edge1/15/2020904
http.headers.Feature-Policy.picture-in-picture 📋Chrome9/4/2018 Edge1/15/2020498
http.headers.Feature-Policy.publickey-credentials-create 📋Edge7/16/2020 Chrome7/27/202011
http.headers.Feature-Policy.publickey-credentials-get 📋Edge7/16/2020 Chrome7/27/202011
http.headers.Feature-Policy.screen-wake-lock 📋Edge7/16/2020 Chrome7/27/202011
http.headers.Feature-Policy.serial 📋Chrome3/2/2021 Edge3/4/20212
http.headers.Feature-Policy.storage-access 📋Chrome5/2/2023 Edge5/5/20233
http.headers.Feature-Policy.usb 📋Chrome7/25/2017 Edge1/15/2020904
http.headers.Feature-Policy.web-share 📋Edge10/9/2020 Chrome10/20/202011
http.headers.Feature-Policy.wildcards Chrome11/29/2022 Edge12/5/20226
http.headers.Feature-Policy.window-management 📋Chrome3/29/2022 Edge4/1/20223
http.headers.Feature-Policy.xr-spatial-tracking 📋Chrome12/10/2019 Edge1/15/202036
http.headers.From 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Host 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.If-Match 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.If-Modified-Since 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.If-None-Match 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.If-Range 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.If-Unmodified-Since 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Integrity-Policy 📋Chrome6/24/2025 Edge6/26/20252
Firefox: Reporting endpoints are ignored (violations are logged to console).Firefox for Android: Reporting endpoints are ignored (violations are logged to console).
http.headers.Integrity-Policy.blocked-destinations_script 📋Chrome6/24/2025 Edge6/26/20252
http.headers.Integrity-Policy-Report-Only 📋Chrome6/24/2025 Edge6/26/20252
Firefox: Reporting endpoints are ignored (violations are logged to console).Firefox for Android: Reporting endpoints are ignored (violations are logged to console).
http.headers.Integrity-Policy-Report-Only.blocked-destinations_script 📋Chrome6/24/2025 Edge6/26/20252
http.headers.Keep-Alive 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Last-Modified 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Link 📋Chrome6/21/2022 Edge6/23/20222
http.headers.Link.fetchpriority 📋Chrome6/21/2022 Edge6/23/20222
http.headers.Location 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.NEL 📋Chrome12/4/2018 Edge1/15/2020407
http.headers.No-Vary-Search 📋Chrome9/30/2025 Edge10/3/20253
Chrome: Before Chrome 127, speculation rules are only supported for navigational prefetch, not prerender.Chrome: Before Chrome 141, HTTP cache is not supported.Chrome Android: Before Chrome Android 127, speculation rules are only supported for navigational prefetch, not prerender.Chrome Android: Before Chrome Android 141, HTTP cache is not supported.Edge: Before Edge 127, speculation rules are only supported for navigational prefetch, not prerender.Edge: Before Edge 141, HTTP cache is not supported.Opera: Before Opera 113, speculation rules are only supported for navigational prefetch, not prerender.Opera: Before Opera 125, HTTP cache is not supported.Opera Android: Before Opera Android 84, speculation rules are only supported for navigational prefetch, not prerender.Opera Android: Before Opera Android 93, HTTP cache is not supported.Samsung Internet: Before Samsung Internet 28.0, speculation rules are only supported for navigational prefetch, not prerender.Samsung Internet: Before Samsung Internet false, HTTP cache is not supported.WebView Android: Before WebView Android 127, speculation rules are only supported for navigational prefetch, not prerender.WebView Android: Before WebView Android 141, HTTP cache is not supported.
http.headers.No-Vary-Search.http_cache 📋Chrome9/30/2025 Edge10/3/20253
http.headers.No-Vary-Search.speculation_rules_prefetch 📋Chrome1/23/2024 Edge1/25/20242
http.headers.No-Vary-Search.speculation_rules_prerender 📋Chrome7/23/2024 Edge7/25/20242
http.headers.Observe-Browsing-Topics Chrome7/18/2023 Edge7/21/20233
http.headers.Origin 📋Chrome12/11/2008 Edge1/15/20204052
Edge: Not sent with POST requestsFirefox: Not sent with POST requests, see bug 446344.Firefox for Android: Not sent with POST requests, see bug 446344.
http.headers.Origin-Agent-Cluster 📋Chrome4/13/2021 Edge4/15/20212
http.headers.Permissions-Policy 📋Chrome1/19/2021 Edge1/21/20212
http.headers.Permissions-Policy.accelerometer 📋Chrome1/19/2021 Edge1/21/20212
http.headers.Permissions-Policy.ambient-light-sensor 📋Chrome4/17/2018 Edge1/15/2020638
http.headers.Permissions-Policy.aria-notify Chrome9/30/2025 Edge10/3/20253
Chrome: Not supported on ChromeOS.Chrome Android: Not supported on ChromeOS.Edge: Not supported on ChromeOS.Opera: Not supported on ChromeOS.Opera Android: Not supported on ChromeOS.WebView Android: Not supported on ChromeOS.
http.headers.Permissions-Policy.attribution-reporting 📋Chrome9/12/2023 Edge9/15/20233
http.headers.Permissions-Policy.autoplay 📋Chrome1/19/2021 Edge1/21/20212
http.headers.Permissions-Policy.bluetooth 📋Chrome8/2/2022 Edge8/5/20223
http.headers.Permissions-Policy.browsing-topics Chrome7/18/2023 Edge7/21/20233
http.headers.Permissions-Policy.camera 📋Chrome1/19/2021 Edge1/21/20212
http.headers.Permissions-Policy.captured-surface-control 📋Chrome4/29/2025 Edge5/1/20252
http.headers.Permissions-Policy.ch-ua-high-entropy-values 📋Chrome1/13/2026 Edge1/21/20268
http.headers.Permissions-Policy.compute-pressure 📋Chrome5/14/2024 Edge5/17/20243
http.headers.Permissions-Policy.cross-origin-isolated 📋Chrome1/19/2021 Edge1/21/20212
http.headers.Permissions-Policy.deferred-fetch 📋Chrome4/1/2025 Edge4/4/20253
http.headers.Permissions-Policy.deferred-fetch-minimal 📋Chrome4/1/2025 Edge4/4/20253
http.headers.Permissions-Policy.display-capture 📋Chrome9/21/2021 Edge9/24/20213
http.headers.Permissions-Policy.encrypted-media 📋Chrome1/19/2021 Edge1/21/20212
http.headers.Permissions-Policy.fullscreen 📋Chrome1/19/2021 Edge1/21/20212
http.headers.Permissions-Policy.gamepad 📋Chrome6/21/2022 Edge6/23/20222
http.headers.Permissions-Policy.geolocation 📋Chrome1/19/2021 Edge1/21/20212
http.headers.Permissions-Policy.gyroscope 📋Chrome1/19/2021 Edge1/21/20212
http.headers.Permissions-Policy.hid 📋Chrome3/2/2021 Edge3/4/20212
http.headers.Permissions-Policy.identity-credentials-get 📋Chrome2/7/2023 Edge2/9/20232
http.headers.Permissions-Policy.idle-detection 📋Chrome9/21/2021 Edge9/24/20213
http.headers.Permissions-Policy.local-fonts 📋Chrome6/21/2022 Edge6/23/20222
http.headers.Permissions-Policy.magnetometer 📋Chrome4/17/2018 Edge1/15/2020638
http.headers.Permissions-Policy.microphone 📋Chrome1/19/2021 Edge1/21/20212
http.headers.Permissions-Policy.midi 📋Chrome1/19/2021 Edge1/21/20212
http.headers.Permissions-Policy.on-device-speech-recognition 📋Chrome10/28/2025 Edge10/31/20253
http.headers.Permissions-Policy.otp-credentials 📋Chrome8/31/2021 Edge9/2/20212
http.headers.Permissions-Policy.payment 📋Chrome1/19/2021 Edge1/21/20212
http.headers.Permissions-Policy.picture-in-picture 📋Chrome1/19/2021 Edge1/21/20212
http.headers.Permissions-Policy.private-state-token-issuance 📋Chrome9/12/2023 Edge9/15/20233
http.headers.Permissions-Policy.private-state-token-redemption 📋Chrome9/12/2023 Edge9/15/20233
http.headers.Permissions-Policy.publickey-credentials-create 📋Chrome1/19/2021 Edge1/21/20212
http.headers.Permissions-Policy.publickey-credentials-get 📋Chrome1/19/2021 Edge1/21/20212
http.headers.Permissions-Policy.screen-wake-lock 📋Chrome1/19/2021 Edge1/21/20212
http.headers.Permissions-Policy.serial 📋Chrome3/2/2021 Edge3/4/20212
http.headers.Permissions-Policy.storage-access 📋Chrome5/2/2023 Edge5/5/20233
http.headers.Permissions-Policy.summarizer 📋Chrome6/24/2025 Edge6/26/20252
http.headers.Permissions-Policy.usb 📋Chrome1/19/2021 Edge1/21/20212
http.headers.Permissions-Policy.web-share 📋Chrome1/19/2021 Edge1/21/20212
http.headers.Permissions-Policy.wildcards Chrome11/29/2022 Edge12/5/20226
http.headers.Permissions-Policy.window-management 📋Chrome3/29/2022 Edge4/1/20223
http.headers.Permissions-Policy.xr-spatial-tracking 📋Chrome1/19/2021 Edge1/21/20212
http.headers.Pragma 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Priority 📋Chrome4/16/2024 Edge4/18/20242
http.headers.Proxy-Authenticate 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.RTT 📋Chrome5/29/2018 Edge1/15/2020596
Chrome: The value is never greater than 3000 ms, as a non-standard anti-fingerprinting measure.Chrome Android: The value is never greater than 3000 ms, as a non-standard anti-fingerprinting measure.Edge: The value is never greater than 3000 ms, as a non-standard anti-fingerprinting measure.Quest Browser: The value is never greater than 3000 ms, as a non-standard anti-fingerprinting measure.Opera: The value is never greater than 3000 ms, as a non-standard anti-fingerprinting measure.Opera Android: The value is never greater than 3000 ms, as a non-standard anti-fingerprinting measure.Samsung Internet: The value is never greater than 3000 ms, as a non-standard anti-fingerprinting measure.WebView Android: The value is never greater than 3000 ms, as a non-standard anti-fingerprinting measure.
http.headers.Range 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Range.cors_safe Chrome3/1/2022 Edge3/3/20222
http.headers.Referer 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Referer.length_limit_4096B Chrome9/10/2019 Edge1/15/2020127
http.headers.Referrer-Policy 📋Chrome1/25/2017 Edge1/15/20201085
http.headers.Referrer-Policy.default_strict-origin-when-cross-origin Chrome8/25/2020 Edge8/27/20202
http.headers.Referrer-Policy.no-referrer-when-downgrade Chrome1/25/2017 Edge1/15/20201085
http.headers.Referrer-Policy.origin-when-cross-origin Chrome1/25/2017 Edge1/15/20201085
http.headers.Referrer-Policy.same-origin Chrome9/5/2017 Edge1/15/2020862
http.headers.Referrer-Policy.strict-origin Chrome9/5/2017 Edge1/15/2020862
http.headers.Referrer-Policy.strict-origin-when-cross-origin Chrome9/5/2017 Edge1/15/2020862
http.headers.Referrer-Policy.unsafe-url Chrome1/25/2017 Edge1/15/20201085
http.headers.Refresh 📋Chrome12/11/2008 Edge7/29/20152421
Firefox: From version 136 the HTTP Referer header is sent following a refresh that redirects to another page (if permitted)Firefox for Android: From version 136 the HTTP Referer header is sent following a refresh that redirects to another page (if permitted)
http.headers.Report-To Chrome10/16/2018 Edge1/15/2020456
http.headers.Reporting-Endpoints 📋Chrome11/15/2021 Edge11/19/20214
http.headers.Retry-After 📋Chrome1/10/2013 Edge10/2/20182091
http.headers.Save-Data 📋Chrome3/2/2016 Edge1/15/20201414
http.headers.Sec-Browsing-Topics Chrome7/18/2023 Edge7/21/20233
http.headers.Sec-CH-DPR 📋Chrome1/4/2022 Edge1/6/20222
http.headers.Sec-CH-Device-Memory 📋Chrome1/4/2022 Edge1/6/20222
Chrome: Before Chrome 147, reported values were 0.25, 0.5, 1, 2, 4, and 8.Chrome: From Chrome 147, reported values are 2, 4, 8, 16, and 32.Chrome: Before Chrome 147, reported values were 0.25, 0.5, 1, 2, 4, and 8.Chrome: From Chrome 147, reported values are 2, 4, 8, 16, and 32.Chrome Android: From Chrome 147, reported values are 1, 2, 4, and 8.Chrome Android: Before Chrome 147, reported values were 0.25, 0.5, 1, 2, 4, and 8.Chrome Android: From Chrome 147, reported values are 1, 2, 4, and 8.Chrome Android: Before Chrome 147, reported values were 0.25, 0.5, 1, 2, 4, and 8.Edge: Before Edge 147, reported values were 0.25, 0.5, 1, 2, 4, and 8.Edge: From Edge 147, reported values are 2, 4, 8, 16, and 32.Edge: Before Edge 147, reported values were 0.25, 0.5, 1, 2, 4, and 8.Edge: From Edge 147, reported values are 2, 4, 8, 16, and 32.Quest Browser: From Chrome 147, reported values are 1, 2, 4, and 8.Quest Browser: Before Chrome 147, reported values were 0.25, 0.5, 1, 2, 4, and 8.Quest Browser: From Chrome 147, reported values are 1, 2, 4, and 8.Quest Browser: Before Chrome 147, reported values were 0.25, 0.5, 1, 2, 4, and 8.Opera: Before Opera false, reported values were 0.25, 0.5, 1, 2, 4, and 8.Opera: From Opera false, reported values are 2, 4, 8, 16, and 32.Opera: Before Opera false, reported values were 0.25, 0.5, 1, 2, 4, and 8.Opera: From Opera false, reported values are 2, 4, 8, 16, and 32.Opera Android: From Chrome 147, reported values are 1, 2, 4, and 8.Opera Android: Before Chrome 147, reported values were 0.25, 0.5, 1, 2, 4, and 8.Opera Android: From Chrome 147, reported values are 1, 2, 4, and 8.Opera Android: Before Chrome 147, reported values were 0.25, 0.5, 1, 2, 4, and 8.Samsung Internet: From Chrome 147, reported values are 1, 2, 4, and 8.Samsung Internet: Before Chrome 147, reported values were 0.25, 0.5, 1, 2, 4, and 8.Samsung Internet: From Chrome 147, reported values are 1, 2, 4, and 8.Samsung Internet: Before Chrome 147, reported values were 0.25, 0.5, 1, 2, 4, and 8.WebView Android: From Chrome 147, reported values are 1, 2, 4, and 8.WebView Android: Before Chrome 147, reported values were 0.25, 0.5, 1, 2, 4, and 8.WebView Android: From Chrome 147, reported values are 1, 2, 4, and 8.WebView Android: Before Chrome 147, reported values were 0.25, 0.5, 1, 2, 4, and 8.
http.headers.Sec-CH-Prefers-Color-Scheme 📋Chrome8/31/2021 Edge9/2/20212
http.headers.Sec-CH-Prefers-Reduced-Motion 📋Chrome11/29/2022 Edge12/5/20226
http.headers.Sec-CH-Prefers-Reduced-Transparency 📋Chrome10/31/2023 Edge11/2/20232
http.headers.Sec-CH-UA 📋Chrome3/2/2021 Edge3/4/20212
http.headers.Sec-CH-UA-Arch 📋Chrome3/2/2021 Edge3/4/20212
http.headers.Sec-CH-UA-Bitness 📋Chrome8/31/2021 Edge9/2/20212
http.headers.Sec-CH-UA-Form-Factors 📋Chrome4/16/2024 Edge4/18/20242
http.headers.Sec-CH-UA-Full-Version 📋Chrome3/2/2021 Edge3/4/20212
http.headers.Sec-CH-UA-Full-Version-List 📋Chrome2/1/2022 Edge2/3/20222
http.headers.Sec-CH-UA-Mobile 📋Chrome3/2/2021 Edge3/4/20212
http.headers.Sec-CH-UA-Model 📋Chrome3/2/2021 Edge3/4/20212
http.headers.Sec-CH-UA-Platform 📋Chrome3/2/2021 Edge3/4/20212
http.headers.Sec-CH-UA-Platform-Version 📋Chrome3/2/2021 Edge3/4/20212
http.headers.Sec-CH-UA-WoW64 📋Chrome3/29/2022 Edge4/1/20223
http.headers.Sec-CH-Viewport-Height 📋Edge9/1/2022 Chrome9/2/20221
http.headers.Sec-CH-Viewport-Width 📋Chrome1/4/2022 Edge1/6/20222
http.headers.Sec-CH-Width 📋Chrome1/4/2022 Edge1/6/20222
http.headers.Sec-Fetch-Dest 📋Chrome2/4/2020 Edge2/7/20203
http.headers.Sec-Fetch-Dest.fencedframe Chrome6/11/2024 Edge6/13/20242
http.headers.Sec-Fetch-Mode 📋Chrome7/30/2019 Edge1/15/2020169
http.headers.Sec-Fetch-Site 📋Chrome7/30/2019 Edge1/15/2020169
http.headers.Sec-Fetch-Storage-Access 📋Chrome2/4/2025 Edge2/6/20252
http.headers.Sec-Fetch-User 📋Chrome7/30/2019 Edge1/15/2020169
http.headers.Sec-Private-State-Token 📋Chrome9/12/2023 Edge9/15/20233
http.headers.Sec-Private-State-Token-Crypto-Version 📋Chrome9/12/2023 Edge9/15/20233
http.headers.Sec-Private-State-Token-Lifetime 📋Chrome9/12/2023 Edge9/15/20233
http.headers.Sec-Purpose 📋Chrome2/7/2023 Edge2/9/20232
http.headers.Sec-Purpose.speculationrules Chrome2/7/2023 Edge2/9/20232
http.headers.Sec-Redemption-Record 📋Chrome9/12/2023 Edge9/15/20233
http.headers.Sec-Speculation-Tags 📋Chrome4/29/2025 Edge5/1/20252
http.headers.Sec-WebSocket-Accept 📋Chrome12/13/2011 Edge7/29/20151324
http.headers.Sec-WebSocket-Extensions 📋Chrome12/13/2011 Edge7/29/20151324
http.headers.Sec-WebSocket-Key 📋Chrome12/13/2011 Edge7/29/20151324
http.headers.Sec-WebSocket-Protocol 📋Chrome12/13/2011 Edge7/29/20151324
http.headers.Sec-WebSocket-Version 📋Chrome12/13/2011 Edge7/29/20151324
http.headers.Server 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Server-Timing 📋Chrome3/6/2018 Edge1/15/2020680
http.headers.Service-Worker 📋Chrome10/7/2014 Edge10/17/20171106
http.headers.Service-Worker-Allowed 📋Chrome4/14/2015 Edge10/17/2017917
http.headers.Service-Worker-Navigation-Preload 📋Chrome6/5/2017 Edge10/2/2018484
http.headers.Set-Cookie 📋Chrome12/11/2008 Edge7/29/20152421
Safari: Cookies with Secure flag are not sent to unsecured http://localhost/ endpoints. See bug 281149.Safari on iOS: Cookies with Secure flag are not sent to unsecured http://localhost/ endpoints. See bug 281149.WebView on iOS: Cookies with Secure flag are not sent to unsecured http://localhost/ endpoints. See bug 281149.
http.headers.Set-Cookie.HttpOnly Chrome12/11/2008 Edge7/29/20152421
http.headers.Set-Cookie.Max-Age Chrome12/11/2008 Edge7/29/20152421
http.headers.Set-Cookie.Partitioned 📋Chrome5/30/2023 Edge6/2/20233
http.headers.Set-Cookie.SameSite 📋Chrome5/25/2016 Edge10/17/2017510
Safari: Safari 13 on macOS 10.14 (Mojave), treats SameSite=None and invalid values as Strict. This is fixed in version 10.15 (Catalina) and later.Safari: Treats SameSite=None and invalid values as Strict in macOS before 10.15 Catalina. See bug 198181.Safari on iOS: Treats SameSite=None and invalid values as Strict in iOS before 13. See bug 198181.WebView on iOS: Treats SameSite=None and invalid values as Strict in iOS before 13. See bug 198181.
http.headers.Set-Cookie.SameSite.Lax Chrome5/25/2016 Edge10/17/2017510
http.headers.Set-Cookie.SameSite.Lax_default Chrome2/4/2020 Edge10/9/2020248
http.headers.Set-Cookie.SameSite.None Edge10/17/2017 Chrome5/29/2018224
Chrome: Rejects cookies with SameSite=None. See SameSite=None: Known Incompatible Clients.Chrome Android: Rejects cookies with SameSite=None. See SameSite=None: Known Incompatible Clients.Quest Browser: Rejects cookies with SameSite=None. See SameSite=None: Known Incompatible Clients.Opera: Rejects cookies with SameSite=None. See SameSite=None: Known Incompatible Clients.Opera Android: Rejects cookies with SameSite=None. See SameSite=None: Known Incompatible Clients.Safari: Not supported before macOS version 10.15 (Catalina).Samsung Internet: Rejects cookies with SameSite=None. See SameSite=None: Known Incompatible Clients.WebView Android: Rejects cookies with SameSite=None. See SameSite=None: Known Incompatible Clients.
http.headers.Set-Cookie.SameSite.Strict Chrome5/25/2016 Edge10/17/2017510
http.headers.Set-Cookie.SameSite.none_requires_secure Chrome2/4/2020 Edge10/9/2020248
http.headers.Set-Cookie.SameSite.schemeful Chrome5/25/2021 Edge5/27/20212
http.headers.Set-Cookie.host_secure_prefixes Chrome3/2/2016 Edge1/15/20201414
http.headers.Set-Cookie.http_host-http_prefixes Chrome9/2/2025 Edge9/5/20253
Firefox: __Host-Http- is supported under its original name __HostHttp-. See bug 1982555.Firefox for Android: __Host-Http- is supported under its original name __HostHttp-. See bug 1982555.
http.headers.Set-Login 📋Chrome12/5/2023 Edge12/7/20232
http.headers.Snapshot-Content-Location Chrome12/6/2017 Edge1/15/2020770
http.headers.SourceMap 📋Chrome3/28/2012 Edge1/15/20202849
Chrome: Not supported for ECMAScript Modules (<script type="module">). See bug 40854862.Chrome Android: Not supported for ECMAScript Modules (<script type="module">). See bug 40854862.Edge: Not supported for ECMAScript Modules (<script type="module">). See bug 40854862.Quest Browser: Not supported for ECMAScript Modules (<script type="module">). See bug 40854862.Opera: Not supported for ECMAScript Modules (<script type="module">). See bug 40854862.Opera Android: Not supported for ECMAScript Modules (<script type="module">). See bug 40854862.Samsung Internet: Not supported for ECMAScript Modules (<script type="module">). See bug 40854862.WebView Android: Not supported for ECMAScript Modules (<script type="module">). See bug 40854862.
http.headers.Speculation-Rules 📋Chrome1/23/2024 Edge1/25/20242
http.headers.Strict-Transport-Security 📋Chrome1/25/2010 Edge7/29/20152011
http.headers.Supports-Loading-Mode 📋Chrome1/10/2023 Edge1/12/20232
http.headers.Supports-Loading-Mode.credentialed-prerender 📋Chrome1/10/2023 Edge1/12/20232
http.headers.Supports-Loading-Mode.fenced-frame 📋Chrome9/12/2023 Edge9/15/20233
http.headers.TE 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Timing-Allow-Origin 📋Chrome10/12/2016 Edge1/15/20201190
http.headers.Transfer-Encoding 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Upgrade 📋Chrome5/25/2010 Edge7/29/20151891
http.headers.Upgrade-Insecure-Requests 📋Chrome7/21/2015 Edge4/30/20181014
http.headers.Use-As-Dictionary 📋Chrome10/15/2024 Edge10/17/20242
http.headers.User-Agent 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Vary 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Via 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Viewport-Width Chrome10/13/2015 Edge1/15/20201555
http.headers.WWW-Authenticate 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.WWW-Authenticate.Basic 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.WWW-Authenticate.Digest 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.WWW-Authenticate.Digest.SHA-256 Chrome9/12/2023 Edge9/15/20233
http.headers.WWW-Authenticate.Digest.md5 Chrome12/11/2008 Edge7/29/20152421
http.headers.WWW-Authenticate.NTLM Chrome12/11/2008 Edge1/15/20204052
http.headers.WWW-Authenticate.Negotiate 📋Chrome12/11/2008 Edge1/15/20204052
http.headers.Warning 📋Chrome12/11/2008 Edge7/29/20152421
http.headers.Width Chrome10/13/2015 Edge1/15/20201555
http.headers.X-Content-Type-Options 📋Edge7/29/2015 Chrome1/23/2018909
Chrome: Not supported for stylesheets.Chrome Android: Not supported for stylesheets.Opera: Not supported for stylesheets.Opera Android: Not supported for stylesheets.Samsung Internet: Not supported for stylesheets.WebView Android: Not supported for stylesheets.
http.headers.X-DNS-Prefetch-Control Chrome12/11/2008 Edge1/15/20204052
http.headers.X-Frame-Options 📋Chrome1/25/2010 Edge7/29/20152011
http.headers.X-Frame-Options.SAMEORIGIN Chrome1/25/2010 Edge7/29/20152011
Chrome: Starting in Chrome 61, this applies to all of a frame's ancestors.Chrome Android: Starting in Chrome Android 61, this applies to all of a frame's ancestors.Firefox: Starting in Firefox 59, this applies to all of a frame's ancestors.Firefox for Android: Starting in Firefox for Android 59, this applies to all of a frame's ancestors.Quest Browser: Starting in Quest Browser 5.0, this applies to all of a frame's ancestors.Opera: Starting in Opera 48, this applies to all of a frame's ancestors.Opera Android: Starting in Opera Android 45, this applies to all of a frame's ancestors.Samsung Internet: Starting in Samsung Internet 8.0, this applies to all of a frame's ancestors.WebView Android: Starting in WebView Android 61, this applies to all of a frame's ancestors.
http.methods.CONNECT 📋Chrome12/11/2008 Edge7/29/20152421
http.methods.DELETE 📋Chrome12/11/2008 Edge7/29/20152421
http.methods.GET 📋Chrome12/11/2008 Edge7/29/20152421
http.methods.HEAD 📋Chrome12/11/2008 Edge7/29/20152421
http.methods.OPTIONS 📋Chrome12/11/2008 Edge7/29/20152421
http.methods.POST 📋Chrome12/11/2008 Edge7/29/20152421
http.methods.PUT 📋Chrome12/11/2008 Edge7/29/20152421
http.mixed-content 📋Chrome12/10/2019 Edge1/15/202036
http.mixed-content.allow_file_urls 📋Chrome12/10/2019 Edge1/15/202036
http.mixed-content.allow_localhost_url 📋Chrome12/10/2019 Edge1/15/202036
http.mixed-content.allow_loopback_url 📋Chrome12/10/2019 Edge1/15/202036
http.mixed-content.auto_upgrade_images 📋Edge10/9/2020 Chrome10/20/202011
Firefox: Set security.mixed_content.upgrade_display_content preference to true to allow HTTP fetching and display of upgradable content.Firefox: Set security.mixed_content.block_display_content preference to true to block all mixed content.Firefox for Android: Set security.mixed_content.upgrade_display_content preference to true to allow HTTP fetching and display of upgradable content.Firefox for Android: Set security.mixed_content.block_display_content preference to true to block all mixed content.
http.mixed-content.auto_upgrade_video_audio 📋Chrome2/4/2020 Edge2/7/20203
Firefox: Set security.mixed_content.upgrade_display_content preference to true to allow HTTP fetching and display of upgradable content.Firefox: Set security.mixed_content.block_display_content preference to true to block all mixed content.Firefox for Android: Set security.mixed_content.upgrade_display_content preference to true to allow HTTP fetching and display of upgradable content.Firefox for Android: Set security.mixed_content.block_display_content preference to true to block all mixed content.
http.mixed-content.block_mixed_downloads 📋Chrome7/20/2021 Edge7/22/20212
http.mixed-content.blockable_mixed_content 📋Chrome12/10/2019 Edge1/15/202036
Chrome: From version 79 blocks iframes, scripts, and stylesheets.Chrome Android: From version 79 blocks iframes, scripts, and stylesheets.Edge: From version 79 blocks iframes, scripts, and stylesheets.Quest Browser: From version 8.0 blocks iframes, scripts, and stylesheets.Opera: From version 66 blocks iframes, scripts, and stylesheets.Opera Android: From version 57 blocks iframes, scripts, and stylesheets.Samsung Internet: From version 12.0 blocks iframes, scripts, and stylesheets.WebView Android: From version 79 blocks iframes, scripts, and stylesheets.
http.mixed-content.private_network_access 📋Chrome6/24/2025 Edge6/26/20252
http.status.103 📋Chrome6/21/2022 Edge6/23/20222
Chrome: Supported in HTTP/2 and later only.Chrome Android: Supported in HTTP/2 and later only.Edge: Supported in HTTP/2 and later only.Quest Browser: Supported in HTTP/2 and later only.Opera: Supported in HTTP/2 and later only.Opera Android: Supported in HTTP/2 and later only.Safari: Supported in HTTP/2 and later only.Safari on iOS: Supported in HTTP/2 and later only.Samsung Internet: Supported in HTTP/2 and later only.WebView Android: Supported in HTTP/2 and later only.WebView on iOS: Supported in HTTP/2 and later only.
http.status.103.preconnect Chrome6/21/2022 Edge6/23/20222
http.status.103.preload Chrome6/21/2022 Edge6/23/20222
http.status.308 📋Chrome7/16/2014 Edge7/29/2015378
Internet Explorer: Does not work below Windows 10.