Verify text compression is actually on

Verify text compression is actually on
Uncompressed HTML/CSS/JS silently triples transfer size and TTFB-to-content. Confirm it per asset, not per assumption.

— Step 1: DevTools Network > add 'Content-Encoding' column. Look for br (Brotli) or gzip on every text asset.
— Step 2: Compare Size vs the uncompressed value in the response — should be 60-80% smaller.
— Step 3: Prefer Brotli (~15-20% under gzip) for static; set quality 11 for cached assets.
— Step 4: Catch the gaps — APIs, JSON, SVG often ship uncompressed.
— Step 5: Re-measure transfer bytes on the critical path.

Example: an uncompressed 280KB JSON -> 44KB Brotli, request time 310ms -> 70ms.

Takeaway: every text response should show br/gzip and shrink 60%+ — anything else is a leak.