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AVIF to WebP converter

Convert AVIF images to WEBP format

No watermarkFree & unlimited
All processing happens in your browser. No data is sent to any server.

These two formats are close cousins, both born from video codecs, and this conversion is the practical compromise between them. WebP shipped years earlier and reaches browsers and operating systems that AVIF still does not, so moving an image across buys reach at the cost of some bytes and one more lossy generation. Transparency survives intact, which is the main reason to pick WebP rather than JPEG as the fallback.

Key facts about AVIF to WebP converter

Key facts about AVIF to WebP converter
Both sides are lossyThe AVIF is decoded and re-encoded with VP8, so this is a transcode rather than a rewrap. Detail lost in the first encode stays lost, and a little more goes.
Size deltaA 120 KB full HD AVIF usually becomes 200 to 300 KB as WebP at quality 90. The gap narrows on flat graphics and widens on noisy photographs.
Support gainedWebP works in Chrome, Edge, Firefox, Opera and Safari 14 upward, plus Windows 10 and macOS Big Sur, where AVIF needs Safari 16 or Firefox 93.
TransparencyKept end to end. AVIF holds alpha as an auxiliary image item and WebP stores it in an ALPH chunk, so a cut-out stays a cut-out.
Lossless not availableA canvas exposes only the lossy WebP encoder, so there is no way to make a pixel-exact WebP of the decoded AVIF from this page.
Quality controlThe slider covers 30 to 100 in steps of 5 and starts at 90, a sensible floor when re-encoding an already compressed source.
AnimationNot carried. An AVIF image sequence is drawn as a single frame, and the canvas cannot write animated WebP even though the format supports it.
When not to convertIf your audience is entirely on current browsers, keep the AVIF and add WebP as an extra source rather than replacing the smaller file.

What happens to your file

Both halves of this conversion are browser work. The AVIF is handed to an Image element through an object URL so the browser's AV1 still-image decoder can produce pixels, and those pixels are drawn onto a canvas created by this page. Asking the canvas for image/webp invokes the WebP encoder built into the same browser. Nothing is posted anywhere, since this page has no endpoint that accepts files.

About this tool

  1. 1

    Drop in the AVIF files

    Up to twenty .avif files per batch, 500 MB each. Drag them onto the target area or click to browse.

  2. 2

    Confirm the decode works

    An empty preview means your browser cannot read AVIF and no conversion is possible; a current Chrome, Firefox or Safari will.

  3. 3

    Choose the quality

    Keep it at 90 or higher, since a low setting compounds artefacts on an already compressed source rather than simply shrinking the file.

  4. 4

    Convert and download

    WebP encoding is fast, so a batch finishes in seconds. Save the file or take converted-webp-files.zip, assembled locally.

Specs & compatibility
Input and outputTakes .avif only (image/avif) and returns .webp with the image/webp type; any other extension is refused before decoding.
Conversion pathAVIF to WEBP runs in three steps: an <img> element decodes the AVIF, which the browser itself must be new enough to read; the pixels land on a 2D canvas in this tab; then canvas.toBlob with the image/webp type returns the finished file.
Browser supportThe AVIF side needs Chrome 85, Firefox 93 or Safari 16.4 to decode, while writing the WebP works in Chromium browsers and Firefox, and where the type is unsupported the canvas specification makes the browser return PNG bytes under the .webp name.
Controls for this pairA 30 to 100 quality slider (steps of five, default 90) drives the WEBP encode, max-dimension presets from 3840 down to 200 px resize the AVIF first, and the strip-metadata toggle is moot on this pair.
Batch, caps and namingTwenty AVIF files per run at 500 MB each; one result downloads as a single WEBP, several as converted-webp-files.zip, zipped by JSZip 3.10 in page memory.
Device ceilingThe canvas caps it: past roughly 16,384 px a side Chromium refuses the bitmap and iPhone Safari gives up sooner, so an oversized AVIF fails before any WEBP bytes exist.
  • Use a picture element with the AVIF first and the WebP second, so modern browsers still get the smaller file.
  • Quality 90 is right when transcoding; the usual advice to drop to 75 assumes an uncompressed original you do not have.
  • If the WebP is larger than expected, the AVIF was encoded aggressively and you are now paying to store its artefacts.
  • For flat graphics and screenshots, compare a PNG too, since lossless may beat both formats on that material.
  • Browser AV1 decode, browser WebP encode
  • Alpha channel preserved across both formats
  • VP8 quality control with a size preview
  • Batch of twenty with an in-browser archive
  • Adding a WebP fallback source to a site that currently serves AVIF only.
  • Getting an AVIF into a content system whose uploader accepts WebP but not AVIF.
  • Standardising a mixed asset folder on the widest-supported format.
Usually one and a half to two times the AVIF at similar visual quality. AV1 intra coding uses more flexible block partitioning and a richer prediction set than VP8, so it reaches the same appearance in fewer bytes. Flat graphics narrow the gap to almost nothing.
A little. This is a transcode between two lossy codecs: the AVIF decodes to pixels that already reflect its compression, and VP8 quantises those again. At quality 90 the second pass is close to invisible; lower settings show the generations compounding in gradients.
No. WebP defines a lossless mode, but browsers do not expose it through canvas.toBlob, the only encoder a page can reach without shipping its own codec. Every WebP produced here is lossy, even at quality 100. For exact pixels, convert to PNG, which the canvas writes losslessly.
Yes, completely. AVIF stores its alpha as a separate auxiliary image item and WebP stores alpha in a dedicated ALPH chunk, and the canvas carries the values between them. That is the practical reason to choose WebP over JPEG when you need a more compatible version of an AVIF.
Usually not. Keep both and let the browser choose, with a picture element listing the AVIF source first and the WebP second. Current browsers then receive the smaller file while everyone else gets a working image. Replacing AVIF outright makes every visitor pay the larger download.

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