Resources for finding browser versions for features

Chrome

• https://storage.googleapis.com/chromium-find-releases-static/index.html

Safari

• https://trac.webkit.org/wiki/PrefixedAPIs
• https://trac.webkit.org/browser/webkit/tags/
• https://trac.webkit.org/browser/webkit/branches/
• https://trac.webkit.org/log/webkit/trunk/Source/WebCore/features.json
• https://trac.webkit.org/log/webkit/trunk/Source/JavaScriptCore/features.json
• https://trac.webkit.org/log/webkit/trunk/Source/WebKit/Shared/WebPreferences.yaml
  (flags for experimental features)

Mapping of Safari Tech Previews to actual Safari releases

From https://github.com/mdn/browser-compat-data/issues/2991

TP versions	Safari version
TP 1-13	Safari 10
TP 14-20	Safari 10.1
TP 21-36	Safari 11
TP 37-47	Safari 11.1
TP 48-58	Safari 12
TP 59-76	Safari 12.1
TP 77-89	Safari 13
TP 90-??	Safari 13.1

Other

• https://lab.syncer.jp/Web/API_Interface/Reference/IDL/ (in Japanese)