WordPress Editor Slow in Brave or Chrome Browsers

Brave Browser is Chrome, with some ad blocking and privacy features enabled by default.

TLDR: Turn off the “Shields Up for this site”, as WordPress uses some scripts heavily to do the editing.

High CPU usage and memory exhaustion in Chrome while using the WordPress 7 editor (Gutenberg) often uses 5GB RAM (on my 16GB RAM system) for that one tab, and runs very slowly. The slowness is most commonly caused by Chrome extensions interfering with the block editor, rather than a WordPress memory leak. 

• Disable Chrome Extensions: Grammar checkers, spell-checkers, and other input-modifying extensions are known to cause significant memory leaks and CPU spikes in the block editor; try disabling them to confirm the fix. 
• Limit Open Tabs: The editor constantly sends requests via WP Heartbeat and admin-ajax.php; opening multiple pages in edit mode or many admin tabs simultaneously drains resources rapidly. 
• Check Plugin Conflicts: Use Query Monitor to identify if a specific plugin or theme is causing high CPU usage during editing sessions. 
• Verify Server Resources: While an 8GB-RAM computer is generally sufficient (but Windows is really faster with 16GB RAM), ensure your hosting plan allows adequate PHP memory limits (e.g., 256MB+) and that OPcache or Redis is enabled on your hosting account to reduce server-side CPU load. 

Brave Browser and other Script-Blocking (Ad-Blocking) Tools

 Brave Browser’s “Shields Up” setting can significantly affect the WordPress Editor (Gutenberg), often causing it to freeze, fail to load, or exhibit high CPU usage. 

How Shields Interfere with the Editor

• Script Blocking: The Gutenberg editor relies heavily on JavaScript files loaded from various sources. Brave Shields may aggressively block these scripts if they are misidentified as trackers or ads, preventing the editor interface from rendering or functioning. 
• admin-ajax.php Interruption: The editor constantly communicates with the server via admin-ajax.php for autosaves, block loading, and updates. Shields can block these background requests, causing the “Background Request Blocked” error or infinite loading spinners. 
• Third-Party Assets: If your editor uses external fonts, icons (like Social Icons blocks), or embedded content, Shields often blocks these resources, leading to layout breaks or miss functionality.

Recommended Solutions

Disable Shields for the Admin Domain:

Click the Lion icon (Shields) in the address bar while on your WordPress admin page.

Toggle Shields DOWN specifically for your site (e.g., yoursite.com).

Refresh the page. This is the most effective fix for editor freezing. 

Adjust Shield Settings Granularly:

If you prefer keeping Shields up, try setting “Trackers & ads blocking” to Standard instead of Strict.

Ensure “Block scripts” is turned OFF for the admin area, as the editor cannot function without scripts. 

Check for Specific Block Issues:

Users have reported that the Social Icons block is specifically targeted by Shields on mobile and desktop.  Disabling shields restores these blocks.

Performance Note

While disabling Shields resolves compatibility issues, be aware that keeping them Up generally improves performance by blocking heavy ad scripts.  However, for the WordPress backend editor, the compatibility cost often outweighs the performance benefit, making it necessary to whitelist the site.