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Why does TH.GL have ad-blocker detection?

GeneralTechnical

The Short Answer

Ads allow TH.GL to be 100% free with no paywalls. Every feature is available to everyone. The detection shows a closable message — it doesn't block you from using the site.

Why Not Just Let Ad Blockers Do Their Thing?

I would — if they only blocked ads. But ad blockers like uBlock Origin and AdGuard actively break website functionality, not just ads:

What Ad Blockers Have Done to TH.GL:
  • Corrupted supporter accounts — uBlock injects fake data into localStorage, overwriting real subscriber data
  • Broke core features — Peer Link, settings dialogs, and whiteboard were hidden by overly broad CSS filters
  • Crashed the site — A uBlock filter with invalid JSON crashed the site for all uBlock users until I caught the error
  • Block privacy-friendly analytics — Self-hosted Plausible (no cookies, no tracking, GDPR-compliant) is blocked
Example of Active uBlock Filter:
th.gl##+js(trusted-set-local-storage-item, account-storage, {...})

This rule overwrites your account data — even if you're a paying supporter. See the commit.

What the Detection Actually Does
  1. Shows a closable message explaining the situation
  2. Links to options: whitelist, subscribe, or keep blocking
  3. Does NOT prevent you from using the site
My Position
  • I'm fine with people blocking ads — as long as they know they're doing it
  • I'm NOT fine with ad blockers breaking functionality and corrupting user data
  • You should be able to make an informed choice

For the full story, see Why Ad Blockers Are Breaking TH.GL.


Why does TH.GL have ad-blocker detection? | FAQ – TH.GL