Caching Strategy: 5 Cache Layers to Make Your Site Lightning Fast

Cache = Memory

Cache stores a previously calculated result so it doesn't have to be recalculated the next time. A correctly configured cache turns a 3-second page into a 0.3-second one.

5 Cache Layers

1. Browser Cache The visitor's browser stores files locally – they won't be reloaded on the next visit.

Cache-Control: public, max-age=31536000, immutable

(1 year for static files)

2. CDN Cache [CDNs](/blogi/cdn-cloudflare-vs-bunny) hold a copy of the server globally. The request only reaches your server if the CDN cannot provide a response.

3. Server-side Page Cache Entire HTML pages are pre-generated and stored.

WordPress plugins: - WP Rocket – premium, the best - W3 Total Cache – free, powerful - LiteSpeed Cache – for LiteSpeed servers - WP Super Cache – official by Automattic

4. Object Cache (Redis/Memcached) Database queries are stored in memory. Critical for active WordPress sites.

# Redis setup on Ubuntu
sudo apt install redis-server

WP plugin: Redis Object Cache.

5. PHP OPcache A pre-compiled version of PHP code in memory. Standard equipment in PHP 7+.

Check: <?php phpinfo(); ?> → search for OPcache.

Recommended config: `ini opcache.enable=1 opcache.memory_consumption=256 opcache.max_accelerated_files=20000 opcache.validate_timestamps=0 ; production `

Cache Invalidation

"There are only two hard things in Computer Science: cache invalidation and naming things." – Phil Karlton.

Rule: every content change invalidates the cache.

Automatic - WordPress: WP Rocket/W3TC invalidates automatically - After post update - After comment

Manual - Admin Bar → Purge cache - Via API call (after deployment) - CLI: `wp cache flush`

Cache Strategy for Different Content

Measurement

Before and after cache configuration:

Common Mistakes

1. Caching dynamic content (cart, login)
2. Cache time too short (missing out on the main cache benefit)
3. Old cache after update (user sees an old version)
4. Same cache for different users (privacy risk)
5. Same cache for mobile/desktop (responsive design solves this)

WooCommerce Specifics

For e-shops: - ❌ Do not cache: cart, checkout, my-account - ✅ Cache: products, categories, homepage - ✅ Fragment caching for dynamic parts

Real-world Example

Client (WooCommerce, 5000 products): - Before: TTFB 1.2s, page loads in 4.8s - After (all 5 layers): TTFB 90ms, page loads in 0.8s - 6x faster

Revenue increased by 18% over the next 30 days.

Summary

Caching is not optional in 2026. Every missing layer costs you customers. See also: - Lazy loading - Core Web Vitals - CDN Comparison

Our optimization service sets up all 5 layers in one week – guaranteed 50%+ speed improvement. Request a quote.

Sources

• Mozilla – HTTP Caching
• Cloudflare – What is Caching?
• WP Rocket – WordPress Caching Guide