(NOTE)
Current policy: <https://www.mediawiki.org/wiki/Compatibility#Browsers>
Affected components: **MediaWiki core, skins and extensions**.
==Motivation
- Improve the user experience by making pages load slightly faster and use less bandwidth, because we're going to send less CSS code (workarounds f.e. on [[ https://caniuse.com/flexbox | Flexbox ]]) down the wire.
- Take away maintenance-burden of writing fallback CSS for newer CSS features not supported in [[ https://docs.microsoft.com/en-us/previous-versions/windows/internet-explorer/ie-developer/dev-guides/hh673549(v=vs.85) | IE9 ]] (f.e. Animations, Hyphenation, text-shadows, ) and [[ https://docs.microsoft.com/en-us/previous-versions/windows/internet-explorer/ie-developer/dev-guides/bg182636(v=vs.85) | IE10 ]] (Flexbox with old 2012 syntax). The effort spent in writing workarounds and addressing specific browser code is a waste of our limited resources.
- Unlock use of newer CSS features that do not have a fallback in IE9 (f.e. Flexbox, Grid layout, multi-column layout) or are a bug-prone maintenance burden in IE10 (f.e. Flexbox with old 2012 syntax). and thus cannot be safely used today.
=== Statistics
[[ https://turnilo.wikimedia.org/#pageviews_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 | Turnilo (restricted) ]] statistics from last 30 days for IE9 & IE10:
2021-10-13: **10.8 million out of 21.3 billion so less than 0.05%**
2021-11-30: **13.5 million out of 21 billion so less than 0.065%**
See also [[ https://analytics.wikimedia.org/dashboards/browsers/#all-sites-by-browser/browser-family-and-major-hierarchical-view | analytics.wikimedia.org ]] for showing no visible significance anymore.
== Proposal
I'm proposing to **remove IE9 and IE10 from “Basic” category in the browser support matrix** and automatically move them to unknown support.
This would be effective in [[ https://www.mediawiki.org/wiki/MediaWiki_1.38 | MediaWiki 1.38 ]], to be released in Spring 2022, in extensions and libraries possibly effective with decision here.