Github
GitHub A/B Test Inconsistent HTML Class Names Break Browser Extensions
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Impact: now it only works if you randomly hit a server that is returning the new class names
From the original report
“a GitHub AB test seems to be causing HTML class names on repo pages to vary between two different options. i updated my extension to fix it, but now it only works if you randomly hit a server that is returning the new class names. annoying”
Details & sources
- How received
- Imported from Bluesky
- Source published
- Oct 15, 2026
- Observed
- Unknown
- Added to CleanApp
- Oct 15, 2026
- Product connection
- Connected service
- Original issue status
- Unknown
- Resolution
- Unknown
- Verification
- Not independently reproduced
Source count unknown
Why this source type: The author personally encountered and investigated an issue where GitHub's varying class names broke their browser extension, observing inconsistent server responses firsthand.
CleanApp AI summary
GitHub A/B Test Inconsistent HTML Class Names Break Browser Extensions: An active A/B test on GitHub repository pages serves differing HTML class names across requests depending on the responding server. This DOM instability breaks third-party browser extensions that depend on predictable element classes.
Report counts are not affected-user counts. A closed original issue does not confirm a fix.
Public ID: rpt_El9QOCXjANGA-bJ-kJszPg