Fix Guide
How to Fix a Slow Initial HTML Response
The initial document request takes long enough to affect perceived performance and crawl efficiency.
Recommended fix
Improve server response time with caching, CDN rules, backend profiling, and redirect cleanup.
This guide is designed to pair with a scanner report. Run a URL scan first, then follow the implementation steps.
Developer task
Measure TTFB at the origin and CDN, then cache public HTML or remove slow backend work before rendering.
Implementation steps
How to apply this fix
- Measure time to first byte at both the origin and the CDN edge.
- Profile the backend to find slow queries, blocking calls, or uncached work before render.
- Enable full-page or fragment caching and CDN caching for public HTML.
- Remove redirect hops that delay the first response.
- Re-scan and confirm the initial HTML response time improves.
Verify
Re-run the URL scan after deploying the change to confirm the issue clears and the Themerella Score updates.
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