AVIF next to WebP and JPEG
The first table converts three test files at AVIF quality 55 and sets them beside WebP at 80 and JPEG at 82. The photo, 694 KB as a JPEG, became 142 KB as AVIF, against 317 KB for WebP and 283 KB for JPEG. The screenshot was 12 KB as AVIF, 29 KB as WebP and 57 KB as JPEG. The illustration was 9.2 KB, 31 KB and 33 KB.
Smaller does not mean identical. The second table shows PSNR, and AVIF at this setting scored 35.3 dB on the photo against 36.8 dB for WebP. PSNR counts pixel differences and ignores how people see, so use the compare slider as the final check. The price of AVIF is time: the photo took 3.3 s to encode.
| Test image | Source | AVIF | WebP | JPEG | AVIF encode time |
|---|---|---|---|---|---|
| Photo | 694 KB | 142 KB | 317 KB | 283 KB | 3.3 s |
| Screenshot | 46 KB | 12 KB | 29 KB | 57 KB | 4.8 s |
| Illustration | 94 KB | 9.2 KB | 31 KB | 33 KB | 1.0 s |
The photo source is a JPEG; the screenshot and illustration sources are PNG. AVIF takes the longest to encode of the formats here. Test images are synthetic files made by this project: a 2000 x 1333 landscape photo, a 1600 x 900 interface screenshot and a 1200 x 1200 transparent illustration. Timings: one thread of WebAssembly on Node v22.23.4, Intel(R) Xeon(R) Processor @ 2.10GHz, 2 cores, measured 2026-10-31. Other devices will differ.
| Test image | AVIF | WebP | JPEG |
|---|---|---|---|
| Photo | 35.3 dB | 36.8 dB | 36.3 dB |
| Screenshot | 44.9 dB | 44.7 dB | 41.0 dB |
| Illustration | 43.0 dB | 43.5 dB | 43.8 dB |
PSNR measures pixel difference, not how a result looks to a person, so use it as a rough guide. The compare slider in the tool shows the real difference.
Choosing a quality
The default is 55. AVIF quality numbers are not the same as JPEG or WebP numbers, so do not carry a number across. Try 45 to 65 and look at the result. Smooth skies and skin tolerate low values. Fine text and hard edges can soften first at low values, so use a higher number there.
Browser and app support
Current versions of Chrome, Firefox, Edge and Safari display AVIF. Many apps, email clients and older systems do not. On a website, offer an AVIF with a WebP or JPEG fallback in a picture element. If you only need one file that works everywhere, WebP is the safer bet.
Speed and memory
The AVIF encoder is a WebAssembly module of about 3.5 MB. It downloads the first time you pick AVIF and is cached for offline use. AVIF is the slowest format to encode here, and big images take several seconds even on a fast machine. On a phone, convert a few images at a time.
When not to use AVIF
Skip it for files headed to print workflows, for lossless archives, and for tools that only read JPEG or PNG. Keep the original image as well. An AVIF is a delivery copy.
Offering AVIF on a site
Put the AVIF first in a picture element, then WebP, then the JPEG as the plain image. A browser takes the first format it understands. Give the image width and height attributes so the layout does not shift, and test on a few devices before you roll it out.
Check each result in the compare view at 100% zoom. Look at gradients and skin for banding or smoothing, since those are the first places AVIF at a low quality lets go of detail.
Questions
Why is AVIF so much smaller?
It uses a newer compression method than JPEG. The numbers in the table come from one run on three test files, so your own files will differ.
Does AVIF keep transparency?
Yes.
Why is the conversion slow?
AVIF encoding is expensive. It runs in a background worker, so the page stays responsive.
Can I aim for a file size?
Yes. Turn on a target size in Advanced settings, under File size.