AVIF

Compress AVIF

Up to 100 files at once. Mixed formats are fine.

Compressing an AVIF re-encodes it at a lower quality, in your browser. Be patient: AVIF encoding is genuinely slow, and that is not a fault — the encoder spending several seconds searching is exactly what produces files smaller than anything else can manage. Nothing is uploaded, and a result that is not smaller than the original is discarded in favour of the original.

The slowness is the feature

AVIF is a still frame of an AV1 video, and AV1 was built for streaming services with server farms and hours to spend. Its encoder considers a great many ways to describe each part of the image and keeps the cheapest, which is why the files are small and why one image can take several seconds in a browser.

A JPEG encoder makes its decisions almost immediately. That difference in effort is most of the difference in file size, and there is no setting that gives you one without the other.

The quality numbers run much lower

AVIF at quality 50 is frequently indistinguishable from the original at the size a web page displays it, which would be visibly damaged as a JPEG. Carrying JPEG instincts across leads to files two or three times larger than they needed to be.

It is especially strong on the things JPEG handles worst: flat colour, gradients, and hard edges between the two. A gradient that bands into visible stripes as a JPEG stays smooth as an AVIF at a fraction of the size.

Where it still is not the answer

Anything that leaves your own website. Email clients do not display AVIF, older operating systems will not open it, and plenty of upload forms reject it outright. For a file that is being sent to somebody, JPEG remains the format that works everywhere, and its universality is worth more than the bytes.

On your own pages, offer AVIF first with a WebP or JPEG fallback underneath. Browsers pick the first one they understand, so the visitors who benefit get the small file and nobody else sees a broken image.

How to compress an AVIF

  1. Drop your AVIF onto this page, or click to choose one.
  2. It is re-encoded in your browser. Expect a few seconds — the encoder is working.
  3. Check the saving, and try a lower quality than you would dare with a JPEG.

Compressing AVIF: common questions

Why is it taking so long?
Because AVIF encoding is computationally expensive, and that is where its small files come from. The encoder is searching through ways to describe the image rather than taking the first workable one. A large photograph can take several seconds per attempt; the tab has not frozen.
Is the image uploaded?
No. libavif runs as WebAssembly in your browser. The slowness is your own processor working, which is also the proof that nothing was sent to a faster one somewhere else.
What quality should I use?
Start lower than feels comfortable — 50 is a reasonable first attempt for a web image, where the same number as a JPEG would look poor. Look at the result at the size it will be displayed rather than zoomed in, and raise it only if something bothers you at that size.
Can everyone open an AVIF?
Every current browser can. Outside browsers, support is patchy: many email clients, older phones and a good deal of desktop software still cannot, so AVIF is a format for your own web pages rather than for files you send to people.

Sometimes the better answer is a different format — especially for a photograph stored as AVIF.