ERR_BLOCKED_BY_CLIENT: What It Means and How to Fix It

What ERR_BLOCKED_BY_CLIENT actually means

Chrome's extension system allows extensions to intercept outgoing requests and block them before any network connection is made. When a request is blocked this way, Chrome shows ERR_BLOCKED_BY_CLIENT in the Network tab and may show a partial page or error depending on how important the blocked resource was. This is not a network problem — your internet connection is fine. It is entirely a browser-side extension decision.

Most likely causes (ranked)

1. Ad blocker (uBlock Origin, AdBlock, AdGuard) matching the request URL against a filter list
2. Privacy extension (Privacy Badger, Ghostery) blocking a tracker or analytics script
3. VPN browser extension with built-in content blocking
4. Corporate security or parental control extension
5. A custom extension filter list rule that matches a legitimate resource

How to fix ERR_BLOCKED_BY_CLIENT

Step 1: Test in incognito mode

Press Ctrl+Shift+N (Windows) or Cmd+Shift+N (macOS) to open an incognito window. Extensions are disabled by default in incognito. If the page loads — an extension is the cause.

Step 2: Identify the blocking extension

Go to chrome://extensions. Toggle extensions off one at a time, reloading the affected page after each. When the page works after disabling a specific extension, that's the culprit.

Step 3: Whitelist the site in your ad blocker

Rather than disabling the extension entirely, whitelist just this site:

• uBlock Origin: Click the icon → click the large power button → reload
• AdBlock/AdBlock Plus: Click icon → "Don't run on pages on this site"
• AdGuard: Click icon → pause protection for this site

Step 4: Use DevTools to find the blocked resource

Press F12 → Network tab → reload the page. Look for entries highlighted in red or showing status "blocked:extension". The URL of the blocked request tells you exactly what the extension is stopping — you can then add that URL to your extension's allowlist.

Step 5: Update filter lists

In uBlock Origin: click the icon → Dashboard → Filter lists tab → Update now. Outdated filter lists sometimes flag legitimate resources as trackers after a site restructures its CDN.

Frequently Asked Questions

Is this always caused by an ad blocker?

Usually, but not always. Any extension using webRequest or declarativeNetRequest can block requests — including privacy tools, VPN extensions, and corporate security extensions. The incognito test confirms whether any extension is responsible.

Why does the whole page fail when only one request is blocked?

Some pages depend on specific scripts to function — a blocked authentication API or core JavaScript file breaks the entire page even though only one request failed. DevTools Network tab shows exactly which request was blocked and whether it's load-critical.