WebP to AVIF Converter
Convert WebP images to AVIF. The output format is preselected for you — just upload, convert and download. Everything runs locally in your browser: your files are never uploaded to a server.
Select images to convert
How to use
Converting WebP to AVIF takes four steps, entirely in your browser.
- Upload your imageUpload your WebP image using the drop zone or Browse files.
- Choose the output formatAVIF is already selected as the output format — no configuration needed.
- ConvertPress Convert; the image is processed locally in seconds.
- Download the resultDownload your new AVIF file.
- Every step runs locally in your browser.
WebP to AVIF: what to expect
Both formats are modern image codecs, so converting one into the other is a measurement to run on your own images — not an automatic upgrade.
When converting WebP to AVIF is actually useful
AVIF and WebP solve the same problem, so it is worth converting when something specific needs AVIF: a host, CDN or image pipeline that only accepts it, an asset set you are standardising on one format, or a size experiment you want to run on real files before you change how you export images.
If you only need broad browser support, WebP already provides it and the conversion changes nothing about how a page behaves. Keep the step in your workflow where AVIF is required or where you have measured a saving on your own images.
Why the file size can go either way
Both codecs discard detail to save space, and AVIF's encoder is generally the more efficient of the two on photographs. But the WebP you upload is already the output of another encoder, and its settings decide how much detail is left to remove.
A WebP exported at a high quality setting usually still has headroom, so the AVIF often ends up smaller. A WebP that was already compressed hard — a common result of automated image pipelines — can come out the same size or larger: the tool decodes those pixels and re-encodes them at its own AVIF quality preset, and detail the original encoding removed cannot come back.
Flat graphics, screenshots and images dominated by uniform colour are where AVIF's advantage is smallest, and very small images can grow because the AVIF container itself carries some overhead.
Encoder effort matters too. This tool encodes AVIF in your browser with an interactive, speed-oriented preset; a desktop encoder given more time can often produce a slightly smaller file from the same pixels.
The practical rule: the size shown for each converted file is the answer for that image. Treat any general statement that AVIF is smaller as a starting point to verify, not a promise.
What the re-encode does to your image
The converter decodes the WebP and encodes those pixels as AVIF at the encoder's fixed quality preset. There is no quality slider on this page, so the same source image always produces the same result — the only variable is the source itself.
Pixel dimensions are copied exactly; nothing is resized or cropped here. That is what makes the before-and-after size comparison meaningful, because both files describe the same number of pixels.
Changing the pixel count usually moves the file size more than changing the codec does. If your AVIF is still too large for its purpose, resizing it or re-exporting the WebP from the original source at a smaller size will do more than converting formats again.
How to check the output size and quality
A short, repeatable check that answers “is this AVIF worth using?” for your own images.
- Convert one file and read the size pairSend a single WebP through the converter first. The uploaded row lists the source size and pixel dimensions, and the result row shows the original size next to the encoded AVIF size — the number that actually matters for your image.
- Compare the two files at 100% zoomDownload the AVIF, keep the original WebP, and open both side by side or in two viewer tabs. Judge them at 100% rather than fit-to-window: scaling down to fit hides exactly the artifacts you are looking for.
- Look where AVIF shows itself firstSmooth gradients and skies for banding, fine texture such as foliage and hair for smearing or blotchy patches, small text and thin high-contrast lines for softening, and the edges of transparent areas for light or dark halos.
- Keep the AVIF only when it passesIf it is smaller and still looks the same at 100%, keep it. If it is larger or visibly worse, keep the WebP — nothing on your device is modified here, so stopping at that point costs you nothing.
- Sample before converting a whole setFor a large batch, run one photo, one screenshot and one graphic first. If those three behave differently, sort the set by type instead of converting everything at once and judging the average.
- Conversion runs entirely in your browser; the original WebP on your device is never altered.
Key Features
Change image format between JPEG/JPG, PNG, WebP, AVIF, BMP and SVG. Every conversion runs locally in your browser — files are never uploaded.
- Browser-based processingConversions run locally — no uploads, ever.
- Full format matrixJPEG/JPG, PNG, WebP, AVIF, BMP and SVG in one place.
- Batch friendlyConvert many images at once and download a ZIP.
- JPEG background controlChoose white or black when flattening transparency.
Supported formats & privacy
What this page handles and how your files are treated.
This page handles WebP to AVIF specifically. The full converter also supports JPEG/JPG, PNG, WebP, AVIF, BMP and SVG. Every conversion runs locally in your browser — files are never uploaded, so the process is private and works offline after load.
Frequently asked questions
No. AVIF often compresses photographs more efficiently than WebP, but this converter decodes the WebP and re-encodes it at a fixed AVIF quality preset, so the result depends on how the WebP was made: a lightly compressed WebP usually shrinks, while one that was already heavily optimised can stay the same size or grow. The original → output size shown on each result row is the reliable answer for your file.
Yes to both. The pixel width and height are copied unchanged — this tool never resizes — and the WebP's alpha channel is encoded into the AVIF. The White/Black background control only appears for JPEG and BMP output, because those formats cannot store transparency.
Current versions of Chrome, Edge, Firefox and Safari all display AVIF, which makes it safe for modern websites and apps. Older browsers and many desktop or office applications cannot open it, so when compatibility matters keep the WebP alongside it as a fallback — a <picture> element with WebP and AVIF <source> entries is the usual pattern.
No. The output is written from the decoded pixels, so EXIF or XMP metadata embedded in the WebP is not copied and the AVIF contains no camera or editing information. Keep the original WebP if you need that data.
AVIF encoding runs locally through a WebAssembly (libavif) codec. The first conversion loads the codec (a moment); after that, encoding is fast and fully offline.
Yes. There is no account, no watermark and no upload: the conversion happens entirely inside your browser.