AVIF Converter

About the AVIF Converter

AVIF is the image format of the AV1 video codec, defined by the Alliance for Open Media. It usually stores photos in fewer bytes than JPG at the same look, keeps transparency like PNG, and opens in current Chrome, Edge, Firefox and Safari.

Drop JPG, PNG, WebP, HEIC or GIF images and they are encoded to AVIF right away, with each file’s size before and after and a slider to compare the result with the original. Or drop AVIF files to turn them into JPG, PNG or WebP for apps that do not open AVIF. Encoding uses your browser’s own AV1 encoder, so nothing is uploaded.

Common uses

• Making lighter images for websites and online shops, so pages load faster.
• Shrinking screenshots and graphics while keeping transparency.
• Opening AVIF images saved from the web in programs that only read JPG or PNG.
• Checking how small an image gets as AVIF before switching a site to it.

How the AVIF files are made

The pictures are encoded as AV1 key frames by the browser’s own AV1 encoder through WebCodecs, with the quality turned into the AV1 quantizer index (0–255) that the WebCodecs AV1 registration defines, the way libavif maps its own quality setting — so similar numbers give similar results, though each encoder makes files of somewhat different sizes. The page converts the colours to Y′CbCr itself (BT.601, sRGB) and writes the AVIF container described in the AV1 Image File Format specification: the image, its size, colour information and, for transparent pictures, the alpha channel as a second AV1 picture.

Choose 4:2:0 for photos (colour stored at half resolution, which the eye barely notices) or 4:4:4 for graphics, text and screenshots, where coloured edges must stay crisp; 4:4:4 is offered where the browser’s encoder supports it.

Which browsers can make AVIF

Making AVIF needs an AV1 encoder that accepts a quality setting. Chrome and Edge on computers have one. Where the browser’s encoder ignores the quality (Firefox, for example) or the browser has none, the page says so and offers JPG, PNG and WebP instead; where the browser can only save AVIF with built-in settings, it uses that and tells you the quality is the browser’s choice. Opening AVIF files and converting them to JPG, PNG or WebP works in every browser that shows AVIF images.

What is kept

Pixels and transparency are kept; photos are turned upright using their EXIF orientation first. Metadata (EXIF, camera details, location) is not copied into the new files, and wide-gamut colours (such as Display P3 photos from phones) are converted to sRGB. Animated GIF, WebP and AVIF files are converted from their first frame.

Limitations

• Lossless AVIF and 10- or 12-bit AVIF are not made; AVIF files are 8-bit.
• Pictures up to 16,384 pixels a side and 70 megapixels can be encoded as AVIF; files up to 200 MB, 100 at a time.
• EXIF and other metadata are not copied to the converted files.

Privacy

Everything happens in your browser. What you enter or open here is not uploaded or stored by MySmartCoPilot.