WooCommerce optimisation

WooCommerce performance is usually a database problem wearing a caching costume. Here is how we approach it.

Measure before you cache

A full-page cache makes the homepage fast and leaves the cart, checkout and account pages slow, because those cannot be cached. If you only measure cached pages you will conclude the site is fine while your actual revenue path is the slowest thing on it.

The usual culprits

In rough order of frequency

• Unindexed queries against wp_postmeta on large catalogues
• Autoloaded options that grow without bound in wp_options
• Plugins loading their assets on every page
• Product queries with no pagination or with meta-based sorting
• Sessions and transients accumulating in the database
• Images served far larger than their rendered size

The work

Index what is queried, stop autoloading options nobody reads, scope assets to the pages that need them, and move session and cache data out of the database if the host allows it. Then re-measure on the pages that were slow, not on the homepage.

When to stop optimising

Performance is a budget, not a score. Decide the threshold where the cost of the next millisecond exceeds the revenue it returns, write it down, and stop there.