Now Stable

"New on the Web": For a given set of browsers, what APIs became stable and when, ordered reverse chronologically.

It's a great source of information for posts like this

Example Comparisons

Stable APIs

Below is a list of features that are in Edge and Firefox, ordered reverse chronologically by when they became stable (i.e, available in the last browser).

2026/1

API	First Browser	Date	Last Browser	Date	Days	Notes
http.headers.Activate-Storage-Access 📋	Edge	2/6/2025	Firefox	1/13/2026	341
http.headers.Sec-Fetch-Storage-Access 📋	Edge	2/6/2025	Firefox	1/13/2026	341

2025/11

API	First Browser	Date	Last Browser	Date	Days	Notes
http.headers.Integrity-Policy 📋	Edge	6/26/2025	Firefox	11/11/2025	138	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 📋	Edge	6/26/2025	Firefox	11/11/2025	138
http.headers.Integrity-Policy-Report-Only 📋	Edge	6/26/2025	Firefox	11/11/2025	138	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 📋	Edge	6/26/2025	Firefox	11/11/2025	138

2025/9

API	First Browser	Date	Last Browser	Date	Days	Notes
http.headers.Set-Cookie.http_host-http_prefixes	Edge	9/5/2025	Firefox	9/16/2025	11	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.

2025/7

API	First Browser	Date	Last Browser	Date	Days	Notes
http.headers.Set-Cookie.Partitioned 📋	Edge	6/2/2023	Firefox	7/22/2025	781

2025/4

API	First Browser	Date	Last Browser	Date	Days	Notes
http.headers.Clear-Site-Data.cache 📋	Edge	1/15/2020	Firefox	4/29/2025	1931	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.Origin-Agent-Cluster 📋	Edge	4/15/2021	Firefox	4/29/2025	1475
http.headers.Set-Login 📋	Edge	12/7/2023	Firefox	4/29/2025	509

2024/10

API	First Browser	Date	Last Browser	Date	Days	Notes
http.headers.Link.fetchpriority 📋	Edge	6/23/2022	Firefox	10/29/2024	859
http.headers.Set-Cookie.SameSite.none_requires_secure	Edge	10/9/2020	Firefox	10/1/2024	1453

2024/9

API	First Browser	Date	Last Browser	Date	Days
http.headers.Content-Security-Policy.report-to 📋	Edge	1/15/2020	Firefox	9/3/2024	1693
http.headers.Report-To	Edge	1/15/2020	Firefox	9/3/2024	1693
http.headers.Reporting-Endpoints 📋	Edge	11/19/2021	Firefox	9/3/2024	1019

2024/7

API	First Browser	Date	Last Browser	Date	Days	Notes
http.headers.Priority 📋	Edge	4/18/2024	Firefox	7/9/2024	82

2024/6

API	First Browser	Date	Last Browser	Date	Days	Notes
http.mixed-content.auto_upgrade_images 📋	Edge	10/9/2020	Firefox	6/11/2024	1341	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 📋	Edge	2/7/2020	Firefox	6/11/2024	1586	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.

2024/5

API	First Browser	Date	Last Browser	Date	Days	Notes
http.headers.Accept-Encoding.zstd 📋	Edge	3/22/2024	Firefox	5/14/2024	53	Safari: Before macOS 26.3 Tahoe, this header value is not sent.
http.headers.Content-Encoding.zstd 📋	Edge	3/22/2024	Firefox	5/14/2024	53	Safari: Before macOS 26.3 Tahoe, Safari cannot decode Zstandard responses.

2024/2

API	First Browser	Date	Last Browser	Date	Days	Notes
http.status.103.preload	Edge	6/23/2022	Firefox	2/20/2024	607

2023/11

API	First Browser	Date	Last Browser	Date	Days	Notes
http.headers.Link 📋	Edge	6/23/2022	Firefox	11/21/2023	516
http.status.103 📋	Edge	6/23/2022	Firefox	11/21/2023	516	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	Edge	6/23/2022	Firefox	11/21/2023	516

2023/10

API	First Browser	Date	Last Browser	Date	Days	Notes
http.headers.Cross-Origin-Embedder-Policy.credentialless 📋	Edge	11/19/2021	Firefox	10/24/2023	704

2023/9

API	First Browser	Date	Last Browser	Date	Days
http.headers.Authorization.Digest.SHA-256	Firefox	10/5/2021	Edge	9/15/2023	710
http.headers.Clear-Site-Data.wildcard 📋	Firefox	10/23/2018	Edge	9/15/2023	1788
http.headers.WWW-Authenticate.Digest.SHA-256	Firefox	10/5/2021	Edge	9/15/2023	710

2023/8

API	First Browser	Date	Last Browser	Date	Days	Notes
http.headers.Range.cors_safe	Edge	3/3/2022	Firefox	8/29/2023	544
http.headers.Content-Security-Policy.script-src.external_scripts 📋	Edge	1/15/2020	Firefox	8/1/2023	1294

2023/7

API	First Browser	Date	Last Browser	Date	Days	Notes
http.headers.Sec-Purpose 📋	Edge	2/9/2023	Firefox	7/4/2023	145

2023/1

API	First Browser	Date	Last Browser	Date	Days	Notes
http.headers.Content-Security-Policy.unsafe-hashes	Edge	1/15/2020	Firefox	1/17/2023	1098

2022/12

API	First Browser	Date	Last Browser	Date	Days	Notes
http.headers.Content-Security-Policy.script-src-attr 📋	Edge	1/15/2020	Firefox	12/13/2022	1063
http.headers.Content-Security-Policy.script-src-elem 📋	Edge	1/15/2020	Firefox	12/13/2022	1063
http.headers.Content-Security-Policy.style-src-attr 📋	Edge	1/15/2020	Firefox	12/13/2022	1063
http.headers.Content-Security-Policy.style-src-elem 📋	Edge	1/15/2020	Firefox	12/13/2022	1063	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.

2022/6

API	First Browser	Date	Last Browser	Date	Days	Notes
http.headers.Content-Security-Policy.script-src.wasm-unsafe-eval	Edge	1/6/2022	Firefox	6/28/2022	173

2021/7

API	First Browser	Date	Last Browser	Date	Days
http.mixed-content.block_mixed_downloads 📋	Firefox	7/13/2021	Edge	7/22/2021	9
http.headers.Sec-Fetch-Dest 📋	Edge	2/7/2020	Firefox	7/13/2021	522
http.headers.Sec-Fetch-Mode 📋	Edge	1/15/2020	Firefox	7/13/2021	545
http.headers.Sec-Fetch-Site 📋	Edge	1/15/2020	Firefox	7/13/2021	545
http.headers.Sec-Fetch-User 📋	Edge	1/15/2020	Firefox	7/13/2021	545

2021/5

API	First Browser	Date	Last Browser	Date	Days	Notes
http.headers.Set-Cookie.SameSite.schemeful	Firefox	7/28/2020	Edge	5/27/2021	303

2021/3

API	First Browser	Date	Last Browser	Date	Days	Notes
http.headers.Content-Length.cors_response_safelist	Edge	1/15/2020	Firefox	3/23/2021	433
http.headers.Referrer-Policy.default_strict-origin-when-cross-origin	Edge	8/27/2020	Firefox	3/23/2021	208

2020/12

API	First Browser	Date	Last Browser	Date	Days	Notes
http.mixed-content.allow_localhost_url 📋	Edge	1/15/2020	Firefox	12/15/2020	335

2020/10

API	First Browser	Date	Last Browser	Date	Days	Notes
http.headers.Set-Cookie.SameSite.Lax_default	Firefox	9/3/2019	Edge	10/9/2020	402

2020/7

API	First Browser	Date	Last Browser	Date	Days	Notes
http.headers.Cross-Origin-Embedder-Policy 📋	Edge	5/21/2020	Firefox	7/28/2020	68
http.headers.Cross-Origin-Opener-Policy 📋	Edge	5/21/2020	Firefox	7/28/2020	68

2020/3

API	First Browser	Date	Last Browser	Date	Days	Notes
http.headers.Cross-Origin-Resource-Policy 📋	Edge	1/15/2020	Firefox	3/10/2020	55	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.

2020/1

API	First Browser	Date	Last Browser	Date	Days	Notes
http.data-url.html_files	Firefox	10/24/2006	Edge	1/15/2020	4831
http.data-url.top_level_navigation_blocked	Firefox	3/13/2018	Edge	1/15/2020	673
http.headers.Access-Control-Allow-Headers.wildcard	Firefox	9/3/2019	Edge	1/15/2020	134
http.headers.Access-Control-Allow-Methods.wildcard	Firefox	9/3/2019	Edge	1/15/2020	134
http.headers.Access-Control-Expose-Headers.wildcard	Firefox	9/3/2019	Edge	1/15/2020	134
http.headers.Alt-Svc 📋	Firefox	5/12/2015	Edge	1/15/2020	1709	Firefox: Only supports draft-04Firefox for Android: Only supports draft-04
http.headers.Authorization.Digest 📋	Firefox	11/9/2004	Edge	1/15/2020	5545
http.headers.Authorization.Digest.md5	Firefox	11/9/2004	Edge	1/15/2020	5545
http.headers.Authorization.NTLM	Firefox	11/9/2004	Edge	1/15/2020	5545
http.headers.Authorization.Negotiate 📋	Firefox	11/9/2004	Edge	1/15/2020	5545
http.headers.Cache-Control.stale-while-revalidate 📋	Firefox	7/9/2019	Edge	1/15/2020	190
http.headers.Clear-Site-Data 📋	Firefox	10/23/2018	Edge	1/15/2020	449
http.headers.Clear-Site-Data.cookies 📋	Firefox	10/23/2018	Edge	1/15/2020	449
http.headers.Clear-Site-Data.secure_context_required	Firefox	10/23/2018	Edge	1/15/2020	449
http.headers.Clear-Site-Data.storage 📋	Firefox	10/23/2018	Edge	1/15/2020	449
http.headers.Content-Security-Policy.base-uri 📋	Firefox	1/13/2015	Edge	1/15/2020	1828
http.headers.Content-Security-Policy.manifest-src 📋	Firefox	9/22/2015	Edge	1/15/2020	1576
http.headers.Content-Security-Policy.report-sample	Firefox	10/23/2018	Edge	1/15/2020	449
http.headers.Content-Security-Policy.strict-dynamic	Firefox	3/7/2017	Edge	1/15/2020	1044
http.headers.Content-Security-Policy.worker-src 📋	Firefox	1/23/2018	Edge	1/15/2020	722	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	Firefox	11/15/2016	Edge	1/15/2020	1156
http.headers.Origin 📋	Firefox	10/22/2019	Edge	1/15/2020	85	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.Referer.length_limit_4096B	Firefox	10/22/2019	Edge	1/15/2020	85
http.headers.Referrer-Policy 📋	Firefox	11/15/2016	Edge	1/15/2020	1156
http.headers.Referrer-Policy.same-origin	Firefox	3/7/2017	Edge	1/15/2020	1044
http.headers.Referrer-Policy.strict-origin	Firefox	3/7/2017	Edge	1/15/2020	1044
http.headers.Referrer-Policy.strict-origin-when-cross-origin	Firefox	3/7/2017	Edge	1/15/2020	1044
http.headers.Server-Timing 📋	Firefox	6/26/2018	Edge	1/15/2020	568
http.headers.Set-Cookie.host_secure_prefixes	Firefox	11/15/2016	Edge	1/15/2020	1156
http.headers.SourceMap 📋	Firefox	8/8/2017	Edge	1/15/2020	890	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.Timing-Allow-Origin 📋	Firefox	3/8/2016	Edge	1/15/2020	1408
http.headers.WWW-Authenticate.NTLM	Firefox	11/9/2004	Edge	1/15/2020	5545
http.headers.WWW-Authenticate.Negotiate 📋	Firefox	11/9/2004	Edge	1/15/2020	5545
http.headers.X-DNS-Prefetch-Control	Firefox	10/24/2006	Edge	1/15/2020	4831
http.mixed-content 📋	Firefox	8/6/2013	Edge	1/15/2020	2353
http.mixed-content.allow_file_urls 📋	Firefox	8/6/2013	Edge	1/15/2020	2353
http.mixed-content.allow_loopback_url 📋	Firefox	8/8/2017	Edge	1/15/2020	890
http.mixed-content.blockable_mixed_content 📋	Firefox	8/6/2013	Edge	1/15/2020	2353	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.

2018/10

API	First Browser	Date	Last Browser	Date	Days	Notes
http.headers.Content-Security-Policy.meta-element-support	Firefox	3/8/2016	Edge	10/2/2018	938

2018/5

API	First Browser	Date	Last Browser	Date	Days	Notes
http.headers.Set-Cookie.SameSite 📋	Edge	10/17/2017	Firefox	5/9/2018	204	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	Edge	10/17/2017	Firefox	5/9/2018	204
http.headers.Set-Cookie.SameSite.None	Edge	10/17/2017	Firefox	5/9/2018	204	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	Edge	10/17/2017	Firefox	5/9/2018	204

2018/4

API	First Browser	Date	Last Browser	Date	Days	Notes
http.headers.Content-Security-Policy.upgrade-insecure-requests 📋	Firefox	11/3/2015	Edge	4/30/2018	909
http.headers.Upgrade-Insecure-Requests 📋	Firefox	8/2/2016	Edge	4/30/2018	636

2018/1

API	First Browser	Date	Last Browser	Date	Days	Notes
http.headers.Content-Security-Policy.frame-ancestors 📋	Edge	4/5/2017	Firefox	1/23/2018	293	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`.

2017/10

API	First Browser	Date	Last Browser	Date	Days	Notes
http.headers.Service-Worker 📋	Firefox	1/26/2016	Edge	10/17/2017	630
http.headers.Service-Worker-Allowed 📋	Firefox	8/11/2015	Edge	10/17/2017	798

2017/4

API	First Browser	Date	Last Browser	Date	Days	Notes
http.headers.Accept-Encoding.br 📋	Firefox	1/26/2016	Edge	4/5/2017	435	Safari: Unsupported before macOS 10.13 High Sierra.
http.headers.Content-Encoding.br 📋	Firefox	1/26/2016	Edge	4/5/2017	435	Safari: Unsupported before macOS 10.13 High Sierra.
http.headers.Content-Security-Policy.child-src 📋	Firefox	3/8/2016	Edge	4/5/2017	393
http.headers.Content-Security-Policy.form-action 📋	Firefox	2/24/2015	Edge	4/5/2017	771

2016/11

API	First Browser	Date	Last Browser	Date	Days	Notes
http.headers.Content-Security-Policy.connect-src 📋	Edge	8/2/2016	Firefox	11/15/2016	105	Firefox: Before Firefox 50, ping attributes of <a> elements weren't covered by connect-src.
http.headers.Content-Security-Policy.sandbox 📋	Edge	8/2/2016	Firefox	11/15/2016	105
http.headers.X-Content-Type-Options 📋	Edge	7/29/2015	Firefox	11/15/2016	475	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.

2016/8

API	First Browser	Date	Last Browser	Date	Days	Notes
http.headers.Content-Security-Policy 📋	Firefox	8/6/2013	Edge	8/2/2016	1092	Internet Explorer: Only supporting 'sandbox' directive.
http.headers.Content-Security-Policy.default-src 📋	Firefox	8/6/2013	Edge	8/2/2016	1092
http.headers.Content-Security-Policy.font-src 📋	Firefox	8/6/2013	Edge	8/2/2016	1092
http.headers.Content-Security-Policy.frame-src 📋	Firefox	8/6/2013	Edge	8/2/2016	1092
http.headers.Content-Security-Policy.img-src 📋	Firefox	8/6/2013	Edge	8/2/2016	1092
http.headers.Content-Security-Policy.media-src 📋	Firefox	8/6/2013	Edge	8/2/2016	1092
http.headers.Content-Security-Policy.object-src 📋	Firefox	8/6/2013	Edge	8/2/2016	1092
http.headers.Content-Security-Policy.report-uri 📋	Firefox	8/6/2013	Edge	8/2/2016	1092
http.headers.Content-Security-Policy.script-src 📋	Firefox	8/6/2013	Edge	8/2/2016	1092
http.headers.Content-Security-Policy.style-src 📋	Firefox	8/6/2013	Edge	8/2/2016	1092
http.headers.Content-Security-Policy-Report-Only 📋	Firefox	8/6/2013	Edge	8/2/2016	1092

2015/7

API	First Browser	Date	Last Browser	Date	Days	Notes
http.data-url 📋	Firefox	10/24/2006	Edge	7/29/2015	3200	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	Firefox	10/24/2006	Edge	7/29/2015	3200
http.data-url.js_files	Firefox	10/24/2006	Edge	7/29/2015	3200
http.headers.Accept 📋	Firefox	11/9/2004	Edge	7/29/2015	3914	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-Encoding 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Accept-Language 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Accept-Ranges 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Access-Control-Allow-Credentials 📋	Firefox	6/30/2009	Edge	7/29/2015	2220
http.headers.Access-Control-Allow-Headers 📋	Firefox	6/30/2009	Edge	7/29/2015	2220
http.headers.Access-Control-Allow-Methods 📋	Firefox	6/30/2009	Edge	7/29/2015	2220
http.headers.Access-Control-Allow-Origin 📋	Firefox	6/30/2009	Edge	7/29/2015	2220
http.headers.Access-Control-Expose-Headers 📋	Firefox	6/30/2009	Edge	7/29/2015	2220
http.headers.Access-Control-Max-Age 📋	Firefox	6/30/2009	Edge	7/29/2015	2220
http.headers.Access-Control-Request-Headers 📋	Firefox	6/30/2009	Edge	7/29/2015	2220
http.headers.Access-Control-Request-Method 📋	Firefox	6/30/2009	Edge	7/29/2015	2220
http.headers.Age 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Authorization 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Authorization.Basic 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Cache-Control 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Connection 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Content-Disposition 📋	Firefox	11/9/2004	Edge	7/29/2015	3914	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 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Content-Language 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Content-Length 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Content-Location 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Content-Range 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Content-Type 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Cookie 📋	Firefox	11/9/2004	Edge	7/29/2015	3914	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.DNT	Firefox	3/22/2011	Edge	7/29/2015	1590
http.headers.Date 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.ETag 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Expires 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.From 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Host 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.If-Match 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.If-Modified-Since 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.If-None-Match 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.If-Range 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.If-Unmodified-Since 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Keep-Alive 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Last-Modified 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Location 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Pragma 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Proxy-Authenticate 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Range 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Referer 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Refresh 📋	Firefox	11/9/2004	Edge	7/29/2015	3914	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.Sec-WebSocket-Accept 📋	Firefox	3/13/2012	Edge	7/29/2015	1233
http.headers.Sec-WebSocket-Extensions 📋	Firefox	3/13/2012	Edge	7/29/2015	1233
http.headers.Sec-WebSocket-Key 📋	Firefox	3/13/2012	Edge	7/29/2015	1233
http.headers.Sec-WebSocket-Protocol 📋	Firefox	3/13/2012	Edge	7/29/2015	1233
http.headers.Sec-WebSocket-Version 📋	Firefox	3/13/2012	Edge	7/29/2015	1233
http.headers.Server 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Set-Cookie 📋	Firefox	11/9/2004	Edge	7/29/2015	3914	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	Firefox	6/17/2008	Edge	7/29/2015	2598
http.headers.Set-Cookie.Max-Age	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Strict-Transport-Security 📋	Firefox	3/22/2011	Edge	7/29/2015	1590
http.headers.TE 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Transfer-Encoding 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Upgrade 📋	Firefox	8/16/2011	Edge	7/29/2015	1443
http.headers.User-Agent 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Vary 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Via 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.WWW-Authenticate 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.WWW-Authenticate.Basic 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.WWW-Authenticate.Digest 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.WWW-Authenticate.Digest.md5	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.Warning 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.headers.X-Frame-Options 📋	Firefox	3/22/2011	Edge	7/29/2015	1590
http.headers.X-Frame-Options.SAMEORIGIN	Firefox	3/22/2011	Edge	7/29/2015	1590	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 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.methods.DELETE 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.methods.GET 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.methods.HEAD 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.methods.OPTIONS 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.methods.POST 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.methods.PUT 📋	Firefox	11/9/2004	Edge	7/29/2015	3914
http.status.308 📋	Firefox	7/17/2012	Edge	7/29/2015	1107	Internet Explorer: Does not work below Windows 10.