Estimate compressed vs uncompressed image size savings across registry transfers.
Docker layers are stored compressed (gzip) in registries. Compressed size = uncompressed / compressionRatio. Typical ratios: 2–3× for compiled binaries, 3–5× for text-heavy layers (node_modules, documentation), 1.2–1.5× for already-compressed data.
Compressed Size
compressed = uncompressed / compressionRatio
`docker images` shows uncompressed size (what's on disk locally); the registry stores gzip-compressed layers, so registry storage and transfer sizes are significantly smaller.
Reducing entropy in layers helps — combining related files, removing unnecessary files before layer commit, and avoiding random/binary content that doesn't compress well.