WordPress Performance Optimization Checklist

Hosting and PHP: confirm PHP version is supported, OPcache is on, and memory limits match your theme and plugin set. Use staging to measure TTFB before and after any change. If TTFB is high on simple pages, fix server and database before micro-optimizing CSS.

Caching: use a consistent full-page cache for anonymous traffic and object cache where the host supports it. Exclude dynamic routes (cart, account, custom APIs) explicitly. Verify cache hit rates under load, not only in a single browser test.

Database: clean excessive revisions, spam, and expired transients on a schedule. Audit slow queries and heavy plugins that run on every request. For large sites, table maintenance and targeted indexing matter.

Assets: convert hero and above-the-fold images to modern formats and explicit dimensions. Defer or async non-critical JavaScript, and load marketing tags after consent and after first paint when possible. Remove unused CSS/JS from page builders by template, not globally in one dangerous purge.

Process: set a performance budget in CI or release checklists for key templates, and re-check after every major plugin or theme update. Checklists work when someone owns them; otherwise the site regresses in six months.