Find and fix a slow website

Optimization starts with a measured bottleneck. More memory or more plugins cannot fix every slow site.

Measure before changing settings

Back up the site, choose a repeatable page or API request, and record load time, server response time, errors, memory and CPU use. Test while signed out and signed in. Change one thing at a time on staging before applying it to production.

Steps

1. Compare cached and uncached requests. Separate DNS/TLS time, server response time and browser rendering using browser network tools.
2. Check Resource usage, disk/inodes and error logs. A repeated resource limit or full disk needs attention before frontend tuning.
3. Measure database queries and slow application routes. Fix unnecessary work before increasing limits.
4. Compress and size images, reduce unused JavaScript, and use versioned assets with suitable cache headers.
5. Cache only responses safe to share. Bypass login, cart, checkout, administration and private API responses.
6. Recheck after updates and monitor error rate and high-percentile response time, not just one best-case speed score.

Choose the next guide

Use the framework guides in Performance. CDN caching may improve static delivery.

Related articles

• Resource usage and logs
• Choose a hosting environment

Last reviewed

2026-10-28