Check encoding first
Text resources usually benefit from gzip, Brotli, or zstd when the server and client negotiate it. Already-compressed images and fonts need different checks.
Performance delivery · compression and cache
Check compression and cache policy for a page or asset
Inspect exact response headers for Content-Encoding, Vary: Accept-Encoding, Cache-Control, immutable assets, validators, declared file size, redirects, and response state without turning them into a fake performance grade.
METHODHEADREDIRECTS5 MAXBODYNOT DOWNLOADED
BR
Ready for a public response.
No sample compression result, cache grade, transfer-savings estimate, Core Web Vitals result, ranking impact, traffic claim, or manufactured performance score appears before a live bounded response check.
Pair header policy with real request evidence
Cache versioned assets longer
Long freshness windows are safest when asset URLs change with content. HTML and unversioned files need more careful invalidation.
Validate with HAR data
Use browser or HAR evidence when you need actual transfer bytes, request counts, protocol labels, cache hits, or Core Web Vitals context.