mdn/browser-compat-data

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Browser compatibility data for Web technologies as displayed on MDN

Stars: 5.8k
Forks: 2.6k
Open beginner issues: 4
Indexed issues: 350
Avg merge: 1d 21h
Merged PRs (30d): 186

Dominant language: JSON
License: CC0-1.0
Last GitHub push: Sep 18, 2026
Latest indexed: Sep 19, 2026
Contributing guide: Contributing guide
Code of conduct: Code of conduct
Beginner labels: help wanted good first issue

Beginner friendly Everything

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40 beginner-friendly issues open

css.properties.display.is_transitionable — Safari 27 disables display transitions for popovers and <dialog> Open

data:css needs triage

Difficulty 2/5 1-3 hours Newbie friendliness 82/100

mdn/browser-compat-data#30560 · Opened Sep 17, 2026
`webdriver.bidi.session.new` - multiple sessions should have a behavioral subfeature Open

blocked data:webdriver

Difficulty 2/5 1-3 hours Newbie friendliness 72/100

mdn/browser-compat-data#30540 · 2 comments · Opened Sep 15, 2026
css.types.line-width - Missing compatibility data Open

browser:multiple data:css needs collector test p3

Difficulty 2/5 1-3 hours Newbie friendliness 68/100

mdn/browser-compat-data#30533 · 2 comments · Opened Sep 15, 2026
margin-trim is only partially supported in Safari Open

browser:safari data:css

Difficulty 2/5 1-3 hours Newbie friendliness 78/100

mdn/browser-compat-data#30528 · 3 comments · Opened Sep 15, 2026
`html.global_attributes.focusgroup` etc. - missing data Open

browser:chrome data:html needs collector test

Difficulty 2/5 1-3 hours Newbie friendliness 70/100

mdn/browser-compat-data#30468 · 1 comment · Opened Sep 10, 2026
<line-width> values for gap, column-gap, and row-gap Open

data:css needs collector test p3

Difficulty 2/5 1-3 hours Newbie friendliness 78/100

mdn/browser-compat-data#30402 · Opened Sep 1, 2026
css.selectors.-webkit-meter-bar - Seems to be incorrectly marked as "deprecated" Open

data:css meeting agenda

Difficulty 2/5 1-3 hours Newbie friendliness 76/100

mdn/browser-compat-data#30317 · 1 comment · Opened Aug 24, 2026
javascript.operators.import - don't cache HTTP errors Open

browser:multiple data:js p3

Difficulty 2/5 1-3 hours Newbie friendliness 72/100

mdn/browser-compat-data#30304 · 1 comment · 1 reaction · Opened Aug 23, 2026
webextensions.api.runtime.onMessage - Respond with Promise is supported since Chromium 148 Open

data:webext p3

Difficulty 2/5 1-3 hours Newbie friendliness 70/100

mdn/browser-compat-data#30194 · 2 comments · Opened Aug 7, 2026
api.ShadowRoot.slotAssignment - `named` value not supported in Chromium 86 Open

data:api needs collector test

Difficulty 2/5 1-3 hours Newbie friendliness 72/100

mdn/browser-compat-data#30182 · 1 comment · Opened Aug 6, 2026
api.fetch - `signal` property is supported by Bun Open

browser:bun data:api p3

Difficulty 2/5 1-3 hours Newbie friendliness 75/100

mdn/browser-compat-data#30151 · 3 comments · 1 reaction · Opened Aug 2, 2026
css.types.image - missing data for `image(<color>)` Open

data:css p3

Difficulty 2/5 1-3 hours Newbie friendliness 68/100

mdn/browser-compat-data#30144 · Opened Jul 30, 2026
api.RTCInboundRtpStreamStats.totalFreezesDuration - Supported in Chrome/Edge/Safari iOS per wpt.fyi Open

browser:multiple data:api needs collector test needs research

Difficulty 2/5 1-3 hours Newbie friendliness 68/100

mdn/browser-compat-data#30039 · 1 comment · Opened Jul 13, 2026
api.WGSLLanguageFeatures - unrestricted_pointer_parameters is supported in safari Open

browser:safari data:api needs collector test p3

Difficulty 2/5 1-3 hours Newbie friendliness 72/100

mdn/browser-compat-data#29989 · Opened Jul 6, 2026
css.properties.column-rule-color - wrong spec and missing feature Open

data:css meeting agenda needs collector test p3

Difficulty 2/5 1-3 hours Newbie friendliness 64/100

mdn/browser-compat-data#29959 · 4 comments · Opened Jul 1, 2026
Update data guideline: Parameters and parameter object features Open

docs:guidelines

Difficulty 2/5 1-3 hours Newbie friendliness 68/100

mdn/browser-compat-data#29856 · 2 comments · Opened Jun 16, 2026
svg.elements.textPath - <Missing lengthAdjust data> Open

browser:multiple data:svg info needed

Difficulty 2/5 1-3 hours Newbie friendliness 68/100

mdn/browser-compat-data#29670 · 1 comment · Opened May 13, 2026
css.types.basic-shape.circle - Values `closest-corner` and `farthest-corner` are not supported by some browsers yet Open

browser:multiple data:css needs collector test

Difficulty 2/5 1-3 hours Newbie friendliness 68/100

mdn/browser-compat-data#29634 · Opened May 8, 2026
css.at-rules.supports.at-rule - missing compat data for @supports at-rule() Open

browser:multiple data:css info needed

Difficulty 2/5 1-3 hours Newbie friendliness 76/100

mdn/browser-compat-data#29549 · 2 comments · Opened Apr 27, 2026
Extend description linter for static API members Open

infra

Difficulty 2/5 1-3 hours Newbie friendliness 75/100

mdn/browser-compat-data#29537 · Opened Apr 24, 2026
api.DeviceOrientationEvent is deprecated on Firefox, but this isn't mentioned on the page Open

browser:firefox data:api p3

Difficulty 2/5 1-3 hours Newbie friendliness 62/100

mdn/browser-compat-data#29409 · 6 comments · Opened Apr 6, 2026
api.Element.animationcancel_event - chromium supports `onanimationcancel` property Open

blocked browser:chrome data:api needs collector update p2

Difficulty 2/5 1-3 hours Newbie friendliness 68/100

mdn/browser-compat-data#29376 · 7 comments · Opened Mar 31, 2026
api.URLPattern - Firefox changed the regex engine Open

browser:firefox data:api p3

Difficulty 2/5 1-3 hours Newbie friendliness 64/100

mdn/browser-compat-data#29092 · 3 comments · Opened Feb 20, 2026
api.VideoTrackGenerator - Wrong browser compatibility report Open

browser:multiple data:api info needed

Difficulty 2/5 1-3 hours Newbie friendliness 68/100

mdn/browser-compat-data#29001 · 5 comments · Opened Feb 9, 2026
css.types.url - missing cross-origin() and referrer-policy() modifiers Open

browser:safari data:css p3

Difficulty 2/5 1-3 hours Newbie friendliness 72/100

mdn/browser-compat-data#28696 · 2 comments · Opened Dec 18, 2025
css.types.color.color-mix - Add support data for optional colorspace argument Open

browser:multiple data:css p3

Difficulty 2/5 1-3 hours Newbie friendliness 82/100

mdn/browser-compat-data#28693 · 9 comments · Opened Dec 18, 2025
api.MediaTrackConstraints.displaySurface - in getDisplayMedia no longer supported on safari Open

data:api info needed

Difficulty 2/5 1-3 hours Newbie friendliness 70/100

mdn/browser-compat-data#30362 · 1 comment · Opened Dec 3, 2025
http.headers.Permissions-Policy - Missing local-network-access Open

browser:chrome data:http

Difficulty 2/5 1-3 hours Newbie friendliness 68/100

mdn/browser-compat-data#28530 · 1 reaction · Opened Nov 25, 2025
webassembly.api.Memory.Memory - Document the compatability status of 4GB heap Open

browser:multiple data:wasm p4

Difficulty 2/5 1-3 hours Newbie friendliness 64/100

mdn/browser-compat-data#27777 · 4 comments · Opened Sep 8, 2025
api.ServiceWorker - WebView on iOS does have support via App Bound Domains Open

browser:webview_ios data:api

Difficulty 2/5 1-3 hours Newbie friendliness 68/100

mdn/browser-compat-data#27470 · 2 comments · Opened Aug 1, 2025
css.at-rules.media.forced-colors - Maybe add a note about Apple devices? Open

browser:safari data:css p4 platform limitation

Difficulty 2/5 1-3 hours Newbie friendliness 72/100

mdn/browser-compat-data#27143 · 3 comments · Opened Jun 25, 2025
css.properties.text-decoration-skip-ink - Safari is not respecting the `none` property Open

browser:safari data:css p4

Difficulty 2/5 1-3 hours Newbie friendliness 74/100

mdn/browser-compat-data#24754 · 5 comments · Opened Oct 18, 2024
html.elements.body - margin attributes compatibility for Chrome is incorrect Open

browser:chrome data:html p4

Difficulty 2/5 1-3 hours Newbie friendliness 68/100

mdn/browser-compat-data#22197 · 4 comments · Opened Feb 11, 2024
api.RTCStatsReport.type_candidate-pair - Missing availableIncomingBitrate compatibility Open

blocked data:api needs expert input p4

Difficulty 2/5 1-3 hours Newbie friendliness 68/100

mdn/browser-compat-data#20594 · 1 comment · Opened Aug 24, 2023
css.properties.justify-self - Missing data for block-level boxes Open

browser:multiple data:css p2

Difficulty 2/5 1-3 hours Newbie friendliness 78/100

mdn/browser-compat-data#20287 · 3 comments · Opened Jul 3, 2023
api.Window.scrollTo - "smooth" behavior supported behind flag Open

browser:chrome data:api

Difficulty 2/5 1-3 hours Newbie friendliness 64/100

mdn/browser-compat-data#20217 · 6 comments · Opened Jun 22, 2023
html.elements.input.type_color - last example does not work in two browsers Open

browser:firefox data:html needs browser bug

Difficulty 2/5 1-3 hours Newbie friendliness 68/100

mdn/browser-compat-data#20077 · 9 comments · Opened Jun 7, 2023
css.types.ratio - `<ratio>` with `<number> / <number>` or `<number>` seems to be supported since Firefox 78 Open

browser:multiple data:css needs collector test

Difficulty 2/5 1-3 hours Newbie friendliness 65/100

mdn/browser-compat-data#18198 · 5 comments · 2 reactions · Opened Nov 11, 2022
http.headers.Content-Security-Policy.report-to - Does not work in Chromium Open

browser:chrome data:http p2

Difficulty 2/5 1-3 hours Newbie friendliness 64/100

mdn/browser-compat-data#18103 · 3 comments · Opened Oct 28, 2022
api.CredentialsContainer.create - passwordCredentials Not Supported - Safari 14 Open

browser:safari data:api good first issue idle

Difficulty 2/5 1-3 hours Newbie friendliness 72/100

mdn/browser-compat-data#7941 · 6 comments · Opened Dec 16, 2020

mdn/browser-compat-data

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