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- losslessly
On the recordRead 12 Oct 202622 facts
losslessly
On the record
- Automation
- The --check option writes nothing and exits with code 1 if any file could shrink, enabling CI checks.github.com · read 4 Oct 2026
- CI and hooks
- A --check mode can fail CI when files could shrink, and the README shows integration with lefthook pre-commit hooks.github.com · read 12 Oct 2026
- Data handling
- The README describes processing local files in place and replacing a file only when the result is smaller.github.com · read 4 Oct 2026
- Formats
- It searches directories recursively for PNG, APNG, JPEG, GIF, WebP and SVG files, with extensions in either case.github.com · read 12 Oct 2026
- GIF limit
- It leaves a GIF alone when its frames exceed the supported palette color count or when a frame turns opaque pixels transparent again.github.com · read 12 Oct 2026
- Image integrity
- PNG, JPEG and WebP output decodes to the same pixels as the input, while GIF output preserves rendered frames and timing.github.com · read 4 Oct 2026
- In-place optimization
- It replaces a file only when the optimized result is smaller and otherwise leaves it byte-for-byte untouched.github.com · read 12 Oct 2026
- Installation
- Prebuilt binaries are offered for macOS and Linux on x86_64 and arm64, and Windows on x86_64; it can also be installed with Cargo.github.com · read 12 Oct 2026
- Integrity checks
- It checks file magic bytes against extensions and reports decoding errors without changing files it cannot process.github.com · read 12 Oct 2026
- License
- The repository is released under the MIT license.github.com · read 12 Oct 2026
- Lossless behavior
- PNG, JPEG and WebP output decodes to the same pixels as input, while GIF output preserves rendered frames and timing.github.com · read 12 Oct 2026
- Maker
- The GitHub profile identifies the maker as Kamil Doroszewicz and lists Poland as the location.github.com · read 4 Oct 2026
- Metadata
- EXIF, ICC profiles, XMP and comments are preserved unless the --strip option is used.github.com · read 12 Oct 2026
- Notable limits
- It does not do lossy compression or format conversion, and AVIF and JPEG XL are not on its roadmap.github.com · read 4 Oct 2026
- Product
- losslessly is a command-line tool that recompresses PNG, JPEG, GIF and WebP files and minifies SVG markup.github.com · read 12 Oct 2026
- Purpose
- losslessly is a command-line image optimizer that recompresses PNG, JPEG, GIF and WebP files and minifies SVG markup.github.com · read 4 Oct 2026
- Safety
- Writes use a temporary file in the same directory and rename it over the original, so the original remains if the process dies mid-write.github.com · read 12 Oct 2026
- Scope
- Lossy compression and format conversion are out of scope, and AVIF and JPEG XL are not on the roadmap.github.com · read 12 Oct 2026
