How to Convert AVIF to JPG or PNG

Steps

1. Open the converter in a browser that supports AVIF (see the next section) and add the AVIF files.
2. Choose JPEG for photographs. Choose PNG for graphics or images with transparent areas.
3. For JPEG, pick the background color that transparent areas should become, and keep the quality at 90 for most pictures.
4. If the file needs to fit a size limit, choose a smaller maximum size too.
5. Check the before and after sizes and download. If the JPG is far larger than you expected, that is normal, and the third section shows why.

Which browsers can open AVIF

The converter relies on your browser to decode AVIF. Support started with Chrome 85, Safari 16.4, Firefox 93 and Edge 121. If you use an older version, the file will not open. Updating the browser is usually enough. There is nothing to configure on the page itself. To test your browser in ten seconds, add one AVIF file: if a thumbnail and a converted size appear, it can read the format; if you see an error for that file, the browser cannot, and the same file will probably not display in that browser's own tabs either.

If you save pictures from websites, you may now and then meet files that look like normal images but are AVIF, since sites choose the format that the visiting browser supports, as the WebP article explains in more detail. An .avif extension or a program complaining about an unknown format is the clue.

Why the JPG is so much bigger than the AVIF

AVIF is built on a modern video codec and is better at compression than JPG, especially for smooth areas. When you convert, the AVIF is expanded to raw pixels and then recompressed in a less efficient way, so the new file grows even though the picture looks the same. I measured it with a synthetic 1920 x 1080 picture of soft shapes on a gradient, encoded with Pillow. At AVIF quality 50 it was 4,913 bytes. Decoded and saved as JPG at quality 90 it was 87,415 bytes (18 times larger), at quality 80 it was 61,635, and as PNG it was 209,124 (43 times larger). At AVIF quality 60: 10,094 bytes, which became 91,427 as JPG at 90.

That picture is smooth and therefore flattering to AVIF, so a real photograph will show smaller ratios. Also, the AVIF quality scale and the JPG one are not comparable, and those AVIF files were of low quality settings. The point stands anyway: expect an increase, possibly several times for smooth pictures, so a limit of a few hundred kilobytes may require reducing the maximum size too.

Choose JPG or PNG

The AVIF is	Output	Why
A photo, destination is a form, email or editor	JPG, 85 to 90	Smallest widely accepted result
A photo you will keep editing	PNG	No further loss on the next save
A graphic or screenshot	PNG	Sharp edges, often smaller than JPG
A cut-out with transparency	PNG	JPG would flatten it onto a color

AVIF supports transparency, so a cut-out AVIF converted to JPG gets the background color you set. How to pick that color is covered in the transparency article.

Why gradients can band after conversion

Color depth is the difference worth knowing. An 8-bit channel has 256 levels, so three channels give 256 x 256 x 256 = 16,777,216 colors. A 10-bit channel has 1,024 levels, over a billion colors in total. If an AVIF was encoded with 10 bits, every step in the converted 8-bit file covers four of the original levels. In a clean blue sky or a studio backdrop, that coarser stepping can show up as faint bands that were not visible in the AVIF. Higher JPG quality does not cure it, because the limit is the 8-bit pixel values and not the compression.

Many AVIFs found on the web are 8-bit and show nothing of this. If you see banding, treat it as a sign that the source had more depth than the output can hold, and keep the AVIF for viewing where it is supported.

When to leave the AVIF alone

Conversion makes sense when a specific program refuses the file. It does not make sense as a habit. If the destination accepts AVIF, as current browsers and many website builders do, the AVIF is smaller, and a JPG made from it is both larger and a generation removed from the original. Scenario: you have a 3000 x 2000 AVIF photo for a marketplace listing that only takes JPG up to 1 MB. Convert at quality 85, pick 2560 pixels as the maximum size (2560 x 1707, about 4.4 megapixels, 73 percent of the original pixel count), and read the size next to the result. If it is still above 1 MB, try 1920 pixels (1920 x 1280, about 2.5 megapixels) before dropping quality below 80.

What can look different afterwards

AVIF can store more than 8 bits per color channel and wide color ranges, including HDR content. The converter's output is 8-bit sRGB with no embedded profile, so a rich, bright AVIF may look flatter or slightly different after conversion; this is a limit of the conversion path, not a fault of the file. The color profile article explains the mechanism. Ordinary photos that were already in sRGB look the same.

An animated AVIF becomes a single still, the first frame. Metadata such as camera information is not carried across either.

Reading the size change on your own file

Because the growth is large, look at the numbers before you upload. Divide the converted size by the AVIF size to get the multiplier, then compare the converted size with the limit you must meet. If you need to cut it down, adjust in this order: first the maximum size, since pixels cost the most; then the quality, in steps of 5; and only last change the format from JPG to PNG if the picture is a graphic, where PNG is often smaller than JPG. Changing from JPG to PNG for a photograph will increase the size again, so that last step belongs to graphics only.

If a form still rejects the result

After conversion check three things in this order: the format the form lists, the size limit, and the pixel dimensions. Many forms accept JPG but not PNG, or the reverse. If the size is the problem, lower the maximum size before the quality; halving the width and height leaves a quarter of the pixels. Details on other causes are in why a website rejects your image.