Supported Formats

Shrinkr can read a wide range of image formats and write to four modern output formats.

Input Formats

Format	Flag value	Notes
WebP	`webp`	Recommended for web. Lossy by default.
AVIF	`avif`	Smallest files. Slower encode.
JPEG	`jpeg`	Universal compatibility.
PNG	`png`	Lossless. May not reach aggressive KB targets.

GIF, AVIF, and HEIF/HEIC images can be compressed and converted to any of the four output formats — they cannot be used as output formats themselves.
Shrinkr uses libvips via the bimg Go wrapper for all image operations.
Files with unsupported extensions are silently skipped.