Note:

• Chrome and Firefox use last 3 year version rule. Currently Safari does not use such rule, probably because Safari in iOS can not be upgraded individually.
• The Grade A and Grade C defined are normative only.
  • It does not define which browser will get JavaScript (which is detected via feature check in startup module)
  • Non-JS features must work in all Grade C browsers, and JS features must work in Grade A browsers (but might work in some Grade C ones)
• Using newer JS features is not only blocked by this requirement, but also blocked by T277675: Add native support for ES2016-ES2017 to the minifier. Currently, only features up to ES7 can be used in Wikimedia code, where all Grade A browsers at least supports ES8.

However for Safari, we will drop support for version <14 completely once T367821: Discovery: Deprecation of TLS 1.2 is resolved.

https://analytics.wikimedia.org/dashboards/browsers/#all-sites-by-browser/browser-family-and-major-hierarchical-view

• Safari iOS 14: 0.38% of Safari iOS users (0.08% of all)
• Safari iOS 12: 0.5% of Safari iOS users (0.1% of all)
• Safari iOS 11, 13: <0.1% of Safari iOS users (<0.02% of all)

• Safari 14: 2% of Safari users (0.072% of all)
• Safari 13: 0.86% of Safari users (0.032% of all)
• Safari 12: 0.16% of Safari users (0.006% of all)
• Safari 11: 0.4% of Safari users (0.014% of all)

Total Safari (macOS, iOS) 11-14: 0.324% of all pageviews

Historically, we've raised the browser support requirements based on a feature we want to use that we think is worth the trade-off. GZWDer is correct that the auto-upgrade features of Chromium- and Firefox-based desktop browsers have meant that we've changed to a rolling three-(ish)-year window, and that doing this for mobile-based devices like iOS Safari and Android Chrome would be a more aggressive change.

Is there a specific feature that is being held back from production by raising iOS and desktop Safari to 15+ (i.e., every other browser including Android 5 support it)?

https://gitlab.wikimedia.org/repos/ci-tools/browserslist-config-wikimedia is where the code version of our standard lives, but let's decide first before writing patches. :-)

• Android 5, released in 2014, supports up to Chrome 95 (released in 2021) (3 years old) as well as the latest version of Firefox (2024)
• iOS 14, released in 2020, supports only Safari 14, also released in 2020.

Chrome and Firefox for Android can be updated through Play Store.

I agree that if there is no specific need for this version bump, it's probably best to wait on T367821 since that will have the same effect on the current matrix.

I'm pretty sure dropping Safari 10 would arguably give us level 1 of CSS Grid which I feel like is a pretty compelling factor, though that's only if you ignore how it's a non-default feature flag for Firefox up to 51 and Chrome up to 56. I'm not sure what the precedent is on whether non-default feature flags count as "support".

In T380344#10349484, @CCiufo-WMF wrote:

I agree that if there is no specific need for this version bump, it's probably best to wait on T367821 since that will have the same effect on the current matrix.

if that's the case, shall this task on Safari versions be stalled then?