cavif — PNG/JPEG to AVIF converter

Encoder/converter for AVIF images. Based on rav1e and avif-serialize via the ravif crate, which makes it an almost pure-Rust tool (it uses C LCMS2 for color profiles).

Installation

➡️ Download the latest release ⬅️

The pre-built zip includes a portable static executable, with no dependencies, that runs on any Linux distro. It also includes executables for macOS and Windows.

Usage

Run in a terminal (hint: you don't need to type the path, terminals accept file drag'n'drop)

cavif image.png

It makes image.avif. You can adjust quality (it's in 1-100 scale):

cavif --quality 60 image.png

Advanced usage

You can also specify multiple images. Encoding is multi-threaded, so the more, the better!

cavif [OPTIONS] IMAGES...

• --quality=n — Quality from 1 (worst) to 100 (best), the default value is 80. The numbers are only a rough approximation of JPEG's quality scale. Beware when comparing codecs. There is no lossless compression support, 100 just gives unreasonably bloated files.
• --speed=n — Encoding speed between 1 (best, but slowest) and 10 (fastest, but a blurry mess), the default value is 4. Speeds 1 and 2 are unbelievably slow, but make files ~3-5% smaller. Speeds 7 and above degrade compression significantly, and are not recommended.
• --overwrite — Replace files if there's .avif already. By default the existing files are left untouched.
• -o path — Write images to this path (instead of same-name.avif). If multiple input files are specified, it's interpreted as a directory.
• --quiet — Don't print anything during conversion.

There are additional options that tweak AVIF color space. The defaults in cavif are chosen to be the best, so use these options only when you know it's necessary:

• --dirty-alpha — Preserve RGB values of fully transparent pixels (not recommended). By default irrelevant color of transparent pixels is cleared to avoid wasting space.
• --color=rgb — Encode using RGB instead of YCbCr color space. Makes colors closer to lossless, but makes files larger. Use only if you need to avoid even smallest color shifts.
• --depth=8 — Encode using 8-bit color depth instead of 10-bit. This results in a slightly worse quality/compression ratio, but is more compatible.

Compatibility

Images work in all modern browsers.

• Chrome 85+ desktop,
• Chrome on Android 12,
• Firefox 91,
• Safari iOS 16/macOS Ventura.

Known incompatibilities

• Windows' preview and very old versions of android are reported to show pink line at the right edge. This is probably a bug in an old AVIF decoder they use.
• Windows' preview doesn't seem to support 10-bit deep images. Use --depth=8 when encoding if this is a problem.

Building

To build it from source you need Rust 1.67 or later, preferably via rustup.

Then run in a terminal:

rustup update
cargo install cavif