How Reverse Proxies Speed Up WordPress: Caching, TTFB, Core Web Vitals
WordPress can be fast without a rebuild. A reverse proxy adds edge caching and origin shielding to improve Core Web Vitals quickly.
Table of Contents
- Why WordPress slows down
- How a reverse proxy helps
- Caching rules that work
- TTFB and LCP improvements
- What to exclude from caching
- Monitoring and tuning
- Performance playbook by role
- Image and asset optimization
- Advanced FAQ
- Why choose BlogPath.io
- Related posts
Why WordPress slows down
- Heavy plugins, chat widgets, unoptimized media.
- PHP rendering on every request; no edge HTML caching.
- Slow database queries and shared hosting bottlenecks.
How a reverse proxy helps
- Edge cache static assets and optionally cache HTML for anonymous users.
- Compress responses (Brotli/Gzip), normalize headers, and minify on the fly.
- Shield origin with WAF/bot filtering to reduce load.
Caching rules that work
- Long TTL for versioned CSS/JS/images; short TTL for HTML.
- Bypass cache on auth cookies; respect cache-control from origin when needed.
- Serve WebP/AVIF when supported; keep JPEG fallback.
TTFB and LCP improvements
- Edge POPs reduce distance; cached HTML slashes TTFB.
- Faster TTFB improves LCP and INP because render starts sooner.
- Use PageSpeed Insights to quantify gains by region.
What to exclude from caching
/wp-admin,/wp-login, search endpoints, carts (if applicable), and form handlers.- Admin AJAX and preview routes; bypass to avoid stale admin states.
Monitoring and tuning
- Track origin CPU/memory; aim for fewer PHP workers in steady state.
- Watch cache hit ratio; add rules for heavy pages.
- Log 4xx/5xx at the edge; fix noisy plugins that block caching.
Performance playbook by role
- For marketers: trim third-party scripts (chat, widgets), and prioritize loading analytics after main content. Add internal links to performance-related posts (
blog-edge-caching-multi-region.md,subdirectory-blog-security.md). - For developers: enable HTTP/2 or HTTP/3, set
stale-while-revalidate, and collapse cache keys to avoid fragmentation. Profile slow PHP queries and offload search to a hosted service if needed. - For ops: set alerts on TTFB, cache hit ratio, 4xx/5xx spikes. Keep DNS TTL at 300s for quick rollback of proxy changes.
Image and asset optimization
- Use responsive images (
srcset) and prefer WebP/AVIF; keep JPEG fallbacks. - Rename files with keywords plus context (e.g.,
wordpress-ttfb-test-2025.jpg), add descriptive alt text, and add captions to hero graphics. - Version static assets to allow long cache TTLs; purge only when versions change.
- Lazy-load below-the-fold images; defer non-critical JS.
- Outbound references for deeper reading: Google CWV, HTTP Archive, Image Optimization.
Advanced FAQ
Can I cache HTML safely?
Yes—cache HTML for anonymous traffic with short TTLs; bypass on auth cookies. Test comment forms and search endpoints.
Do I still need a caching plugin?
You may keep one, but avoid conflicting headers. Let the edge proxy own caching and keep plugin output simple.
How to handle personalized widgets?
Bypass cache on paths or cookies that serve personalized content; consider edge-side includes only if necessary.
How to measure wins?
Compare before/after TTFB and LCP in multiple regions. Look for higher cache hit ratio and reduced origin CPU.
Why choose BlogPath.io
- Global CDN caching with sane defaults for WordPress, without writing Nginx/Worker configs.
- Origin shielding and WAF reduce load and attacks.
- Observability: cache hits, errors, and Web Vitals surfaced; no DIY logging stack.
- Zero-code DNS cutover keeps your theme/plugins intact while improving speed.