Actual PikoZip worker functions with pinned WASM codecs in a Node harness. PNG decoded using UPNG; canvas copies decoded RGBA without resizing. Timings are shared-runner measurements, not browser/device guarantees. Codec quality 85 is not equal visual quality across formats. Not a TinyPNG comparison.

Run npm ci and node scripts/publish-compression-evidence.mjs in the matching source checkout. Inspect actual outputs and originals before choosing a mode. Numbers do not establish perceptual equivalence or universal savings.