AVIF Converter — JPG, PNG, WebP to AVIF

Why convert images to AVIF?

AVIF is a modern image format based on the AV1 video codec. At the same visual quality it is typically much smaller than JPG and noticeably smaller than WebP, and it supports transparency, wide color and high dynamic range. Smaller images mean faster page loads, better Core Web Vitals scores, lower bandwidth bills and less storage. This AVIF converter lets you turn existing JPG, PNG and WebP files into AVIF, and turn AVIF files back into PNG when a program cannot open them.

Everything happens locally. The first time you convert an image, the page loads a WebAssembly build of the libavif encoder (via the jsquash project) from this website. After that, each image is decoded, compressed and packaged on your own device — nothing is uploaded, so there are no size limits, queues or privacy concerns. You can drop many files at once; each row in the table shows the original size, the new size and the percentage saved.

Quality, speed and lossless mode

The quality slider trades size for fidelity. Values around 50–60 are a good default for photographs; artifacts are hard to spot while savings compared with JPG are often 50% or more. Screenshots, diagrams and images with small text may need a higher value. Encoder speed ranges from 0 (slowest, smallest file) to 10 (fastest). The default of 6 is a sensible balance; very large photos encode faster at 8–10. Lossless keeps every pixel exactly, which suits graphics and archiving, but the files are much larger than lossy AVIF.

Using AVIF on the web

All current major browsers display AVIF, but some older apps, email clients and editors do not. On a website you can serve AVIF with a fallback using the picture element: list the AVIF source first and a JPG or WebP image as the default. Keep your originals, compare the result visually before replacing files, and remember that re-encoding an already heavily compressed JPG cannot restore lost detail — start from the best source you have.