Browser ERR_BLOCKED_BY_CLIENT — What It Means & How to Fix It

Fix browser ERR_BLOCKED_BY_CLIENT error when an ad blocker or browser extension prevents network requests from completing. This guide covers everything you need to know about this topic, including common causes, step-by-step solutions, and answers to frequently asked questions.

Here are the key things to understand: ERR_BLOCKED_BY_CLIENT appears in Chrome DevTools when a browser extension blocked a network request. The most common cause is ad blocker extensions (uBlock Origin, Adblock Plus) filtering out requests. The error can affect legitimate resources if the ad blocker's filter lists are too aggressive. This error only appears in the browser's developer tools Network tab, not as a visible error page. Understanding these fundamentals will help you diagnose and resolve this issue more effectively.

The most common reasons this occurs include: Ad blocker extension blocking a request that matches its filter rules. Privacy extension (Privacy Badger, Ghostery) blocking tracking-related domains. Custom browser extension with request interception blocking the URL pattern. Browser's built-in tracking protection blocking third-party requests. Identifying the root cause is the first step toward finding the right solution.

To resolve this, follow these recommended steps: Open DevTools (F12) > Network tab to identify which specific request was blocked. Temporarily disable ad blocker extensions to confirm they are the cause. Add the affected domain to your ad blocker's allowlist/whitelist. If developing a website, ensure critical resources are not served from ad-network-like domains. If these steps do not resolve the issue, consider consulting additional resources or a qualified professional.

This article is part of our Browser Errors collection on Error Codes Wiki. We provide comprehensive, up-to-date information to help you find solutions quickly.