Updated · how we check
Convert AVIF to WebP free, without uploading
AVIF to WebP grew our 1281×1600 px test portrait from 58.9 KB to 110 KB (+87%). Quality stays high unless you set a KB limit. Drop the AVIF (.avif) on the tool below and download the WebP; nothing is uploaded.
AVIF to WebP
WebP · no file-size limit · original pixel size
No file-size limit is set: PixelFit saves at high quality and changes only the format and any pixel size you set.
Fit, background and padding white background
Saving presets is part of Pro.
The result appears here: the exact byte count, pixel size and quality, the size before and after, a preview and a download button.
The batch kit (one ZIP for up to 500 photos, several photos merged into one PDF) is part of Pro.
What changes from AVIF to WebP
5 of these 6 points lose or alter something on the way from AVIF to WebP; the rest carry over.
- Kept: Transparency survives: WebP keeps the alpha channel of the AVIF.
- Lost or changed: AVIF can be animated; PixelFit writes a still WebP of the first frame only.
- Lost or changed: AVIF can be lossy or lossless and most AVIF files online are lossy, so saving one as WebP usually adds a second round of compression loss; keep quality high.
- Lost or changed: AVIF can hold more than 8 bits per channel (8, 10 or 12 bits per channel); a browser canvas works at 8 bits, so 10-, 12- or 16-bit files are reduced to 8 bits per channel.
- Lost or changed: Metadata is not carried over: the AVIF's EXIF and XMP items are dropped by the canvas, and EXIF orientation is applied to the pixels first so the photo stays upright.
- Lost or changed: WebP allows at most 16,383 pixels per side, so larger images have to be scaled down to fit.
Measured file size: AVIF vs WebP
sharp 0.35.5 / libvips 8.18.7, 31 October 2026, long edge 1600 px; WebP saved as quality 85, alpha kept, AVIF as quality 50, effort 4 (PixelFit reads AVIF but does not write it). The WebP column is the AVIF file decoded and saved again, as PixelFit does.
| Sample | AVIF | WebP | Change |
|---|---|---|---|
| portrait photo (1281×1600 px) | 58.9 KB (60,328 bytes) | 110 KB (113,022 bytes) | +87% |
| landscape photo (1600×1200 px) | 239 KB (244,291 bytes) | 514 KB (526,306 bytes) | +115% |
| scanned typed letter (1273×1600 px) | 99.1 KB (101,466 bytes) | 166 KB (169,534 bytes) | +67% |
| flat chart with a transparent background (1600×1000 px) | 5.7 KB (5,794 bytes) | 15 KB (15,316 bytes) | +164% |
What the numbers mean for AVIF to WebP
Our portrait photo at 1281×1600 px: AVIF 58.9 KB → WebP 110 KB (+87%, 1.9 times larger).
Our landscape photo at 1600×1200 px: AVIF 239 KB → WebP 514 KB (+115%, 2.2 times larger).
Our scanned typed letter at 1273×1600 px: AVIF 99.1 KB → WebP 166 KB (+67%, 1.7 times larger).
Our flat chart with a transparent background at 1600×1000 px: AVIF 5.7 KB → WebP 15 KB (+164%, 2.6 times larger).
Per pixel, the portrait took 0.24 bits as AVIF and 0.44 bits as WebP, a difference of 51.5 KB on 2,049,600 pixels.
Per pixel, the chart took 0.03 bits as AVIF and 0.08 bits as WebP, a difference of 9.3 KB on 1,600,000 pixels.
WebP came out larger than AVIF on all 4 samples, by +67% to +164%.
For comparison, the original portrait saved directly as a quality 85 JPG was 254 KB and as a quality 85 WebP 141 KB, −44% against the JPG.
How to convert AVIF to WebP
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Add the AVIF file
Drop the .avif file on the tool at the top of this page, tap to choose it, or paste it.
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Keep WebP selected
WebP is pre-selected at quality 85. Type a maximum size in KB or exact pixel dimensions only if the destination sets them; PixelFit then searches the highest quality that fits and shrinks the pixel size only when quality alone is not enough. Our AVIF test portrait came out at 110 KB as WebP with no limit set.
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Download the WebP
Save the file ending in .webp; its size in KB shows before you save.
AVIF and WebP side by side
AVIF (2019) next to WebP (2010); browser figures checked 31 October 2026.
| Property | AVIF | WebP |
|---|---|---|
| File extensions | .avif | .webp |
| MIME type | image/avif | image/webp |
| Compression | lossy or lossless | lossy or lossless |
| Transparency | yes | yes |
| Animation | yes | yes |
| Largest size | 2,147,483,647 px per side | 16,383 px per side |
| Colour depth | 8, 10 or 12 bits per channel | 8 bits per channel |
| Metadata | EXIF and XMP items | EXIF, XMP and ICC chunks |
| First published | 2019 | 2010 |
| Opens in | Chrome 85+, Edge 121+, Firefox 93+, Safari 16.4+; about 96.33% of browsers in use | Chrome 32+, Edge 18+, Firefox 65+, Safari 16+ (Safari 14-15 only on macOS 11 or later); about 97.08% of browsers in use |
| Good for | modern websites that want the smallest photos | web pages, where it is usually smaller than JPEG and keeps transparency |
| Weak for | older apps, photo editors and most upload forms, which do not open it | government and exam forms, which often accept only JPG or PDF |
| Specification | AV1 Image File Format (AVIF), Alliance for Open Media | RFC 9649: WebP Image Format (IETF) |
When not to change AVIF to WebP
- Do not change AVIF to WebP to make a photo smaller: our portrait grew +87%, from 58.9 KB to 110 KB, with no gain in quality.
- Do not send WebP to exam, visa or job-portal forms unless they list it: most accept only JPG, JPEG or PDF. Safari cannot write WebP from a canvas and PixelFit stops there with a message, so run this AVIF to WebP step in Chrome, Edge or Firefox on a computer or Android phone; on iPhone and iPad every browser uses Safari's engine, so save JPG or PNG there.
- If the destination already accepts AVIF, upload the original: every change of format re-encodes the pixels.
Browser support for AVIF and WebP (October 2026)
Reading AVIF (.avif): Chrome 85+, Edge 121+, Firefox 93+, Safari 16.4+. caniuse puts AVIF support at about 96.33% of browsers in use (data updated 29 October 2026).
Writing WebP from that AVIF: Chrome 50+, Edge 79+, Firefox 96+; Safari cannot encode it (its canvas hands back a PNG), and on iPhone and iPad every browser, Chrome and Firefox included, uses Safari's engine, so PixelFit stops there and suggests JPG instead of saving a PNG under a .webp name (MDN compatibility data for canvas.toBlob, checked 31 October 2026).
AVIF reached Safari later than Chrome and Firefox, so iPhones and Macs older than Safari 16.4 may not open it; current versions do.
Where AVIF files come from
AVIF files mostly come from websites that serve the newest image format to modern browsers. Saving one gives you an .avif that many desktop apps and forms cannot open, so it is changed to WebP for reuse.
Sources
- AV1 Image File Format (AVIF), Alliance for Open Media, Alliance for Open Media, checked 31 October 2026: aomediacodec.github.io/av1-avif/
- RFC 9649: WebP Image Format (IETF), IETF, checked 31 October 2026: rfc-editor.org/rfc/rfc9649
- caniuse.com “AVIF image format” support table, data of 29 October 2026 (CC BY 4.0): caniuse.com/avif
- MDN browser-compat-data, HTMLCanvasElement.toBlob (which browsers write WebP), CC0, checked 31 October 2026: github.com/mdn/browser-compat-data/blob/main/api/HTMLCanv…
- Test photo “President Barack Obama.jpg” by Pete Souza (Official White House photo), public domain, measured by PixelFit with sharp 0.35.5 / libvips 8.18.7 on 31 October 2026: commons.wikimedia.org/wiki/File:President_Barack_Obama.jpg
Frequently asked questions
Can I convert AVIF to WebP for free?
Yes. The AVIF to WebP change runs free on your device, with no sign-up and no upload, one file or up to 25 at a time; Pro raises the batch to 500 with one ZIP download.
How do I convert AVIF to WebP?
Drop the AVIF on the tool above, keep WebP selected, and download the .webp file. Add a KB limit if the destination has one.
Does converting AVIF to WebP reduce quality?
AVIF can be lossy or lossless and most AVIF files online are lossy, so saving one as WebP usually adds a second round of compression loss; keep quality high. In our test a 1281×1600 px portrait went from 58.9 KB as AVIF to 110 KB as WebP (+87%).
Why convert AVIF to WebP?
WebP suits web pages, where it is usually smaller than JPEG and keeps transparency; AVIF is a poor fit for older apps, photo editors and most upload forms, which do not open it.
Related
More AVIF format changes
- AVIF to JPG same AVIF input
- AVIF to PNG same AVIF input
Other files to WebP
- SVG to WebP also ends as WebP
- PNG to WebP also ends as WebP
- JPG to WebP also ends as WebP