WordPress Database Optimisation: How to Clean Up and Speed Up Safely

On this page

1. What bloats a WordPress database
2. Always back up first
3. Safe clean-up steps
4. Limit revisions going forward
5. Be careful with leftover tables and options
6. Autoloaded options
7. WooCommerce stores
8. How often?

Every WordPress site stores its content and settings in a database. Over the years it collects clutter: hundreds of post revisions, expired temporary data, spam comments and leftovers from plugins you deleted long ago. On older and busier sites, cleaning it up can make the dashboard and uncached pages noticeably quicker.

What bloats a WordPress database

• Post revisions: WordPress saves a copy every time you update a page
• Auto-drafts and trashed posts
• Spam and trashed comments
• Expired transients: temporary cached data that hasn't been cleared
• Leftover plugin data: tables and settings from removed plugins
• Autoloaded options: settings loaded on every page; too many slow every request
• Logs: some security, email and scheduling plugins keep large logs

Always back up first

Database clean-up deletes data permanently. Take a full backup and confirm you can restore it before you start; see backup and restore guide.

Safe clean-up steps

1. Delete spam and trashed comments
2. Empty the trash for posts and pages
3. Remove old revisions, keeping a few recent ones
4. Clear expired transients
5. Optimise database tables

Plugins such as WP-Optimize or Advanced Database Cleaner can do this, and some caching plugins include database tools. Run the clean-up, then remove or deactivate the tool if you don't need it regularly.

Limit revisions going forward

You can limit how many revisions WordPress keeps by adding a line to wp-config.php, for example keeping the last five. Ask your developer if you're not comfortable editing this file.

Be careful with leftover tables and options

Removing data left by old plugins helps, but deleting the wrong table can break a working feature. Only remove leftovers you're sure belong to plugins you no longer use, or have a developer review them.

Autoloaded options

If a plugin stores large amounts of data as autoloaded options, every page load pays the price. Recent versions of WordPress Site Health can warn when autoloaded data is too large. Fixing it usually means removing or replacing the plugin responsible.

WooCommerce stores

Stores accumulate customer sessions, order notes and scheduled action logs. WooCommerce has built-in tools to clear some of these under WooCommerce → Status → Tools. Never delete order data without accounting approval.

How often?

For most business sites, a clean-up every few months is plenty. See the maintenance checklist.

Database work is one part of speed; also see caching explained and why your site is slow.