ERR_BLOCKED_BY_CLIENT with AdBlocker

TL;DR

With an adblocker enabled, posthog.init succeeds but loading assets (e.g. from eu-assets.i.posthog.com) fails with ERR\BLOCKED\BY\_CLIENT, and PostHog keeps throwing/retrying errors.

Steps

1. Maintainer marandaneto closed it stating the only reliable solution is the reverse proxy (https://posthog.com/docs/advanced/proxy), which hides the PostHog domains so adblockers can't match them. Maintainer ioannisj added: bundle the SDK extensions into your own app (npm install posthog-js instead of the CDN snippet) so /static/*.js requests never happen, or use the prepare_external_dependency_script init hook to rewrite asset paths through your proxy.

When to use

You are seeing this: Maintainer marandaneto closed it stating the only reliable solution is the reverse proxy (https://posthog.com/docs/advanced/proxy), which hides the PostHog domains so adblockers can't match them. Use this skill when you run into "ERRBLOCKEDBY_CLIENT with AdBlocker".

When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

Versions

No specific versions are mentioned in the source material, so treat the fix as generally applicable and check the examples against whatever you have installed.

Why this happens

The original report does not dig into a root cause. It documents the symptom and the fix that resolved it.

Sources

• https://posthog.com/docs/advanced/proxy

In gh:PostHog/posthog-js#2866 (https://github.com/PostHog/posthog-js/issues/2866), the question was: With an adblocker enabled, posthog.init succeeds but loading assets (e.g. from eu-assets.i.posthog.com) fails with ERR_BLOCKED_BY_CLIENT, and PostHog keeps throwing/retrying errors. The verified resolution: Maintainer marandaneto closed it stating the only reliable solution is the reverse proxy (https://posthog.com/docs/advanced/proxy), which hides the PostHog domains so adblockers can't match them. Maintainer ioannisj added: bundle the SDK extensions into your own app (npm install posthog-js instead of the CDN snippet) so /static/*.js requests never happen, or use the prepare_external_dependency_script init hook to rewrite asset paths through your proxy.