The site shipping 900KB of uncompressed text

The site shipping 900KB of uncompressed text

A jobs board in Nairobi served fast images but slow pages on mobile networks. The culprit was 900KB of HTML, CSS, and JSON going over the wire raw.

We ran a compression tuning checklist:

— Confirmed which responses had Content-Encoding — half had none
— Enabled Brotli at the edge for text types: HTML, CSS, JS, JSON, SVG
— Set Brotli level 5 for dynamic responses (fast) and level 11 for static, cached assets (max ratio)
— Excluded already-compressed types — JPEG, PNG, WebP — from re-compression
— Verified compressed sizes in a repeat fetch, not just that the header appeared

Text payload dropped from 900KB to 210KB. On a 3G connection in Nairobi that was three seconds off load time. Brotli at level 11 only makes sense for cached static files — recompressing dynamic HTML at 11 per request burns CPU for little gain. Tier the level by whether the response is cached.

The number that mattered: 690KB of text removed from every cold page load.