The block-rate report
Which analytics tools are actually blocked?
Measurement is just getting started, so there isn't enough data to publish a ranking yet. Run the live demo to see detection in your own browser.
Block rate by provider
- —
Optimizely
Optimizely runs A/B tests and feature experiments. When its CDN is blocked, experiment assignment and conversion tracking silently stop.
- —
PostHog
PostHog is a product-analytics and session-recording platform. Blocked users send no events, so funnels and retention undercount.
- —
Google Analytics 4
Google Analytics 4 is Google's web and app analytics. It is one of the most aggressively blocked endpoints on the web.
- —
Google Tag Manager
Google Tag Manager loads your other tags. When GTM itself is blocked, every tag it manages goes dark at once.
- —
Segment
Segment is a customer-data pipeline that fans events out to other tools. A block at the source starves everything downstream.
- —
Hotjar
Hotjar records heatmaps and session replays. Blocked sessions never appear in your recordings.
- —
Amplitude
Amplitude is a product-analytics platform. Blocked clients drop out of every behavioral report.
- —
Mixpanel
Mixpanel is an event-analytics platform. Blocked users are invisible to its funnels and cohorts.
- —
Meta Pixel
The Meta Pixel powers Facebook and Instagram ad attribution. When it is blocked, conversions go unreported and ad optimization degrades.
- —
Intercom
Intercom powers in-app chat and messaging. A blocked widget means those users can't reach support through it.
"—" means we don't yet have enough measured samples to publish a trustworthy rate for that provider. Prefer raw data? Get it as JSON.
How we get the number right
Detecting ad and content blockers is genuinely hard: a blocked request and a network error look alike, filter lists match domains rather than filenames, and loader snippets keep a global defined even when the CDN behind them is blocked. A naive "is the global truthy?" check reports loaded for blocked users and quietly undercounts the real block rate.
blockrate is built to avoid that. It checks each provider's real post-load global (not the loader stub), uses per-provider ground-truth probes against the actual CDN, and reports through a first-party endpoint so the measurement itself isn't the thing getting blocked. The result is a number you can trust per provider — which is the whole point. Read how it works.
Measure your own stack
These are aggregate numbers. Your audience is more technical or more privacy-minded than average, so your real block rate is probably higher. blockrate is an open-source library that measures it, per provider, on your own site.