What this problem looks like
Page cache stores HTML files. Object cache stores database query results. Opcode cache stores compiled PHP. CDN cache stores static assets at the edge. Each needs a separate purge command.
Clearing cache does not fix underlying bugs, but it stops false negatives when you test fixes. Always purge after plugin updates, CSS changes, or menu edits.
Page cache plugins
WP Rocket, LiteSpeed Cache, W3 Total Cache, WP Super Cache, and SiteGround Optimizer each expose a Purge or Clear cache button. Use Clear all, not only homepage. Some plugins add an admin bar link labelled Purge SG Cache or Delete cache.
- Log into wp-admin.
- Open your cache plugin settings.
- Click purge all or clear cache and minified CSS.
- Confirm success notice appears.
Object cache and Redis
If Redis or Memcached is active, flushing only page cache leaves stale options and transients. Use hosting panel flush object cache or WP-CLI when available.
wp cache flush
wp transient delete --allHosting and CDN layers
Cloudflare: Caching → Configuration → Purge everything, or purge by URL for surgical tests. LiteSpeed servers cache outside WordPress. Use LiteSpeed Web Admin or host support to purge.
Do not purge CDN during a flash sale unless necessary. Full purges increase origin load temporarily.
Opcode and PHP caches
OPcache stores compiled PHP. After deploying code via FTP, changes may not appear until OPcache resets. Restart PHP-FPM from hosting or wait for TTL. Some hosts offer a Reset PHP cache button.
Verify cache is actually cleared
Open the site in a private window. In DevTools Network tab, enable Disable cache, reload, and check response headers. Look for cache HIT from CDN or age headers that should reset after purge.
When to stop DIY and hire help
If purging cache does not reflect code changes, you may have multiple unknown cache layers or a misconfigured CDN. BugShield audits cache stacks on UK WordPress and WooCommerce sites.