WebP to AVIF Converter — Convert WebP to AVIF Online
Drop your file below and pick AVIF as the output format — free, private, and entirely in your browser. Lower the quality slider to 85% before you convert. Your WebP is already compressed, and at the default 92% the AVIF comes out roughly 19% larger; at 85% it comes out 21% smaller.
Drop images here or click to browse
Supports HEIC, WEBP, AVIF, BMP, TIFF, SVG, GIF, ICO, PDF, JPG, PNG
100% Private — Your files never leave your device
All conversion happens directly in your browser using JavaScript. Nothing is uploaded to any server. Your images stay on your computer the entire time.
When to Use AVIF Over WebP
AVIF, built on the AV1 codec, compresses harder than WebP's VP8-derived codec. Encoding this site's 1600 × 2000 test photograph from the original, AVIF at 85% quality produces a 189.6 KBfile measuring 49.20 dB PSNR, while WebP at 92% produces 245.5 KBat 47.36 dB. The AVIF is 22.8% smaller and closer to the original. That is the case for AVIF, and it is real.
It is also not a reason to convert everything. Reach for AVIF when:
- You are serving photographs on a website and bandwidth is the constraint. The saving is largest exactly where payloads are biggest.
- You compress aggressively. AVIF's lead widens as quality drops — it holds detail together at settings where WebP starts to fall apart.
- You can serve a fallback. A
<picture>element with AVIF first and your existing WebP second costs nothing and covers the last few percent of browsers.
Stay on WebP when encoding speed matters — AVIF is several times slower to encode — when you need animation, which this converter cannot carry across, or when your WebP files already load fast enough. WebP is not a legacy format, and a page that already ships WebP is not slow. For the full side-by-side, see WebP vs AVIF.
One caveat specific to this conversion: a WebP has already thrown detail away. Converting it to AVIF is a lossy-to-lossy transcode, so you never quite match what you would get by encoding AVIF from the original master. If you still have that master, start there instead — PNG to AVIF or JPG to WebP cover the common cases.
File Size Comparison
Every number below is measured, not estimated. The source is this site's 1600 × 2000 test photograph saved as a WebP at 92% quality — 245.5 KB — then run through the converter above at each slider position. The PSNR column compares the AVIF against that source WebP — the higher the number, the closer the copy, with the mid-40s and above generally taken as hard to tell apart by eye.
| Quality setting | AVIF size | vs the 245.5 KB WebP | PSNR vs WebP |
|---|---|---|---|
| 50% | 41.8 KB | 83.0% smaller | 39.9 dB |
| 75% | 122.7 KB | 50.0% smaller | 44.9 dB |
| 85% | 193.5 KB | 21.2% smaller | 47.8 dB |
| 90% | 264.4 KB | 7.7% larger | 50.2 dB |
| 92% (default) | 293.3 KB | 19.4% larger | 51.0 dB |
The table crosses over between 85% and 90%. Above that line the encoder is spending bits to reproduce the WebP's own compression artefacts faithfully — you are paying to preserve damage. This is not a quirk of one photograph: the other two photos on this site behave the same way, growing 20.5% and 18.5% at the default setting and shrinking by 26.0% and 9.1% at 85%.
So the useful range for this conversion sits at 85% and below. At 85% you save a fifth of the bytes at a fidelity no one will see through. At 75% you halve the file. At 50% you cut it by more than four fifths, and on a photograph the result still holds up on a web page — though that is the point where you should look at it yourself rather than trust a number.
Two things worth knowing about that quality dial. It is not a shared scale between codecs, so “AVIF at 85” and “WebP at 85” are not the same request. And it has no lossless position: this converter encodes AVIF with 4:2:0 chroma subsampling at every setting, so even 100% discards some colour resolution while inflating the file to 609.5 KB. There is no setting at which the AVIF is a faithful archive of your WebP.
Browser Support Table
Both formats work in every current browser. WebP got there first, and AVIF took five years to close the gap — Edge was the last holdout, enabling it by default only in January 2024.
| Browser | WebP since | AVIF since |
|---|---|---|
| Chrome | 23 (November 2012) | 85 (August 2020) |
| Edge | 18 (November 2018) | 121 (January 2024) |
| Firefox | 65 (January 2019) | 93 (October 2021) |
| Safari (iOS) | iOS 14 (September 2020) | iOS 16 (September 2022) |
| Safari (macOS) | 14 (September 2020) | 16.4 (March 2023) |
The versions above are for still images, which is what this converter produces. Animated and lossless WebP landed later — Chrome 32 and Safari 16 respectively — which is why caniuse.com quotes a stricter 96% of global traffic for WebP against roughly 93% for AVIF.
A three point gap sounds like nothing until you multiply it by your traffic. Keep the WebP files you already have and add AVIF beside them in a <picture>element — AVIF first, WebP second — and every visitor gets the smallest file their browser can read. Outside the browser, support thins out fast: Windows needs the AV1 Video Extension before Photos will open an AVIF, and plenty of desktop editors still refuse it. If the file has to open on someone else's machine, send the WebP.
How to Convert WebP to AVIF
- Drag your WebP file into the drop zone, or click to browse and select it.
- Choose AVIF from the Output Format menu.
- Drag the Quality slider down to 85% or lower — at the default 92% the AVIF will be larger than the WebP you started with.
- Download the AVIF — it's saved straight to your device.
The converter shows the before and after size for every file, so you can see immediately whether the setting you picked actually saved anything. Drop several WebPs at once and take them away together as a ZIP. Nothing is uploaded: the AVIF encoder is libavif compiled to WebAssembly and runs on your own machine. Expect a large image to take a few seconds — AV1 compression is doing real work.
Frequently Asked Questions
Why is my AVIF bigger than the WebP I started with?
Because you left the quality slider at its default. This site's 1600×2000 test photo, saved as a 245.5 KB WebP, comes back as a 293.3 KB AVIF at the default 92% — 19.4% larger. Two things cause it. The quality number is not a shared scale: 92 asks far more of the AVIF encoder than it does of WebP's, so AVIF spends bits faithfully reproducing the WebP's own compression artefacts. And your source is already lossy, so there is far less redundancy left to squeeze than a camera original would have. Step the slider down to 85% and the same file lands at 193.5 KB — 21.2% smaller — with no visible difference. We reproduced the same effect on two other photos on this site: both grew about 20% at 92% and shrank at 85%.
Is AVIF actually smaller than WebP?
Yes, but you have to compare at equal quality rather than at equal slider positions. Encoding this site's test photograph straight from the original, WebP at 92% gives 245.5 KB measuring 47.36 dB PSNR. AVIF at 85% gives 189.6 KB measuring 49.20 dB — 22.8% smaller and nearly 2 dB more faithful. Line the two codecs up on the same dial instead and the comparison is meaningless, because at 92% AVIF is aiming at a much higher fidelity target than WebP is.
Does converting WebP to AVIF lose quality?
Yes, and twice over — this is a lossy-to-lossy transcode, so the AVIF is a compressed copy of an already-compressed image. The good news is that the second generation costs very little. Our source WebP measures 47.36 dB PSNR against the original photograph. Re-encoded to AVIF at 85%, it measures 46.42 dB against that same original: under 1 dB of extra loss for a 21% smaller file. Convert from the original master rather than the WebP whenever you still have it, and never transcode the same image back and forth repeatedly.
Does AVIF support transparency like WebP?
Yes. Both formats carry a full alpha channel and this converter encodes it, so a WebP with a transparent background becomes an AVIF with the same transparent background. Alpha is encoded at the same quality as the colour channels. Nothing is flattened onto white, which is what would happen if you converted to JPG instead.
Can I convert an animated WebP to an animated AVIF?
No. This converter draws your image onto a canvas, which captures a single frame, so an animated WebP comes out as a still AVIF of its first frame. The AVIF container can hold animation, but encoding it needs a full AV1 video encoder rather than the still-image encoder that runs here. If you need the animation preserved, keep the WebP.
Which browsers support AVIF in 2026?
All of the current ones. Chrome has supported AVIF since version 85 (August 2020), Firefox since 93 (October 2021), Safari since 16.4 on macOS and iOS 16, and Edge since 121 (January 2024) — Edge was the last major holdout. Per caniuse.com that works out to roughly 93% of global browser traffic, against about 96% for WebP. That remaining gap is why the standard advice is to serve AVIF from a picture element with a WebP fallback rather than replacing your WebP files outright.
Why is the first conversion slower than the others?
The AVIF encoder is a 3.3 MB WebAssembly module that downloads the first time you pick AVIF, then stays in memory for the rest of the session. Encoding is also genuinely slow work: AVIF uses the AV1 codec's intra-frame compression, which searches much harder for redundancy than WebP's VP8-derived codec does. A multi-megapixel image takes a few seconds. That search is exactly what buys you the smaller file.
Can I convert AVIF back to WebP?
You can, and the AVIF to WebP converter on this site does it, but understand what you get: a third generation of lossy compression. Nothing that AVIF discarded comes back. Keep whatever original the WebP was made from and treat both the WebP and the AVIF as derivatives you can regenerate at will.