How to Clear and Manage Broken Link Checker Database Tables

Many WordPress users rely on the Broken Link Checker plugin to maintain site integrity, but over time, its database tables can grow significantly. This can lead to concerns about database optimization and backup sizes. This guide explains how to safely manage and clean these tables without breaking plugin functionality.

Why Broken Link Checker Tables Grow Large

The Broken Link Checker plugin creates several database tables to track links throughout your website. The main tables include:

• wp_blc_links - Stores information about each detected link
• wp_blc_instances - Tracks where links appear in your content
• wp_blc_synch - Manages synchronization data
• wp_blc_filters - Stores custom link filters

Additionally, the plugin creates a blc_installation_log entry in your wp_options table, which can sometimes become quite large (up to 455KB as reported by users).

How to Safely Clean Broken Link Checker Data

Option 1: Complete Plugin Reset

If you want to start fresh with Broken Link Checker, you can safely remove its data by:

1. Deactivating the plugin from your WordPress dashboard
2. Using phpMyAdmin or similar database management tool to delete these tables:
   • wp_blc_filters
   • wp_blc_instances
   • wp_blc_links
   • wp_blc_synch
3. Removing the blc_installation_log record from your wp_options table
4. Reactivating the plugin, which will recreate empty tables

Option 2: Partial Cleanup

If you prefer to keep your plugin settings but want to reduce database size:

1. You can safely truncate or delete records from the wp_blc_links table specifically
2. The plugin will regenerate link data during its next scan
3. You can set the blc_installation_log option to autoload=no to prevent it from loading with every page

Important Considerations

• Back up your database before making any changes
• Deleting tables will remove all your current link data and settings
• The plugin will need to rescan your entire site after cleaning the database
• If you use the plugin infrequently (e.g., every 6 months), consider deactivating it between uses to prevent table growth

Compatibility Note

Some users have reported compatibility issues with migration plugins like Duplicator when Broken Link Checker tables contain data. If you're planning to migrate your site, consider cleaning these tables beforehand or temporarily deactivating the plugin during the migration process.

By regularly managing your Broken Link Checker database tables, you can maintain optimal website performance while still benefiting from the plugin's link monitoring capabilities.