tech

How to fix: Server response time (TTFB) <=800ms

Why this matters

Time to First Byte is when the server delivers the first byte of HTML to the browser. <=800ms is Google's Good threshold; >1800ms is Poor. TTFB is the foundation of every other performance metric — a slow server negates frontend optimisations.

Background

TTFB is when the server delivers the first byte of HTML. <=800ms = Good; >1.8s = Poor. TTFB is the foundation of every other performance metric — a slow server negates every frontend optimisation.

References

web.dev/ttfb · Core Web Vitals supplementary metric

How to fix

Code snippet for each stack we cover. Pick the one matching your server / framework.

nginx

Enable proxy_cache for cacheable responses. Use `worker_processes auto` + tune `worker_connections`. HTTP/2 + keepalive.

apache

mod_cache + mod_disk_cache. Tune MPM worker config.

cloudflare

Page Rules → Cache Everything for cacheable pages. APO on the Pro plan handles WordPress edge caching.

wordpress

Object cache (Redis Object Cache plugin). Page cache (WP Rocket / W3 Total Cache). Move heavy plugins (slow DB queries, external API calls) off the critical render path.

flask

Profile slow endpoints with `werkzeug.contrib.profiler`. Cache DB queries with Flask-Caching. Move slow work to Celery background tasks.

express

Profile with `clinic.js doctor`. Use Redis for session + query caching.

rails

Rails.cache.fetch around expensive queries. New Relic / Skylight for endpoint profiling.

Verify it's working

https://pagespeed.web.dev/ TTFB metric, OR `curl -w '%{time_starttransfer}' -o /dev/null -s https://your-site/` — should be <0.8s.

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