Convert AVIF to JPG

How to convert AVIF to JPG

1. Choose one or more AVIF images — drag them in or use the file picker.
2. Set the JPG quality if you want a smaller file or sharper output.
3. Download the JPG — a single file, or a zip if you converted several at once.

A browser decodes AVIF; the canvas writes the JPEG because it cannot write AVIF

AVIF is AV1’s intra-frame coding — superblocks up to 128 pixels across, brought from video to a single still — wrapped in the HEIF container HEIC also uses. It has an animated variant too, and this converter keeps only the first frame. A browser that ships the AV1 decoder opens such a file; its canvas can encode only PNG, JPEG and WebP, never AVIF, so the page decodes with the browser’s own decoder and writes the result as a JPEG.

PNG is the only type a browser is required to be able to write; JPEG rides alongside it on every engine, Safari included, where WebP output is absent from the canvas entirely. That guarantee is why the download here is a real JPEG, not the PNG a canvas quietly substitutes when asked for a format it cannot make — which is exactly what AVIF is. And unlike that lossless PNG, the JPEG is a lossy encode, which is why it exposes a quality setting the PNG never would.

The two codecs sit on opposite ideas, so the re-encode is a real recoding, not a container swap. AV1 predicts a block from as many as 56 directional angles across those large superblocks; the JPEG re-expresses the decoded pixels as fixed 8×8 DCT blocks, each block’s average brightness stored as a difference from the previous one, with colour typically shared across 16×16-pixel groups at 4:2:0 subsampling. None of AVIF’s adaptive structure survives — a 1992 block transform is what the file carries out.

Ten bits per channel is 1,024 levels; the baseline JPEG keeps 256

A 10-bit AVIF stores 1,024 levels per channel — AV1’s Main and High profiles both allow it, and the sequence header can flag BT.2020 primaries or a PQ or HLG curve beside them. Baseline JPEG, the flavour a browser’s canvas writes, is an 8-bit format fixed since 1992: 256 levels per channel and no field for that colour signalling. Most AVIF on the web is already 8-bit, but when a 10-bit master arrives, three of every four code values are resolved away before the JPEG is written.

Smooth gradients are where 256 levels give out. A clear sky, a sunset, softly lit skin — a forehead or an out-of-focus shoulder — may cross only a few dozen distinct values over a couple of thousand pixels, so neighbours round to the same number and the eye reads the joins as stripes. Foliage and fabric hide the same rounding, because their own fine detail scatters the contour. Worse, JPEG’s lossy quantisation coarsens those low-frequency regions further, so banding can surface in the JPEG where the AVIF looked clean.

Colour behaves the same way. A canvas works in sRGB unless a page asks otherwise, so a wide-gamut or HDR AVIF is mapped into sRGB before encoding, and a red outside the sRGB triangle must land somewhere inside it — engines make that choice differently. The resulting JPEG is an 8-bit sRGB file with nowhere to record the primaries or transfer curve it dropped. Because that encode is lossy and one-way, the AVIF master is the only place the wider range still exists.

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