Will AVIF always be smaller than WebP?
No. Size depends on the source encoding, image content and chosen AVIF quality. The result list shows whether each output is smaller or larger.
Batch AVIF encoding
WebP to AVIF Converter
Re-encode WebP images as adjustable-quality AVIF files and compare the real output sizes.
Last updated: August 2026
Batch
WebP files
60
Default quality
1–100
Quality range
Private
No uploads
60
Smaller fileBetter quality
AVIF encoding is compute-intensive. Conversion may take 5 to 30 seconds per image. All processing runs in your browser.
Drop WebP files here or click to browse
All processing stays in your browser. Nothing is uploaded.
How to convert WebP to AVIF
01
Set AVIF quality
Choose a value from 1 to 100 before adding files; the default is 60.
02
Add WebP files
Select one or more WebP images. Each accepted file begins converting immediately.
03
Wait for AVIF encoding
The browser decodes pixels and uses the WebAssembly encoder at speed 8.
04
Compare and download
Review each size result, download files individually or bundle multiple AVIFs in a ZIP.
What the converter actually does
Decode then re-encode
The source WebP is decoded to RGBA pixels before AVIF encoding.
Quality 1–100
The default value is 60 and is captured when files are added.
Speed-8 encoding
The AVIF encoder favors faster browser conversion over its slowest mode.
Batch workflow
Every accepted WebP is converted as its own result.
Real size comparison
The list reports whether each AVIF became smaller, equal or larger.
Still output
Animation and source metadata are not transferred to the new AVIF.
Common WebP-to-AVIF mistakes
Assuming AVIF must be smaller
A higher-quality AVIF can exceed an efficiently encoded WebP.
Changing quality after adding files
Existing conversions are not automatically restarted.
Expecting lossless transcoding
The source is decoded and encoded again with the selected AVIF quality.
Expecting animation
The conversion produces a still AVIF.
Adding too many large images
Parallel browser work can exhaust memory or slow the device.
Expecting source metadata
The encoder receives pixels, not the WebP metadata container.
Why use ImgTweak?
✓Batch WebP input
✓AVIF quality from 1 to 100
✓Speed-8 local encoding
✓Per-file size comparison
✓Individual or ZIP download
✓No uploads or account required
Frequently asked questions
What AVIF quality is used?
The default is 60 and the slider ranges from 1 through 100. The value is captured when files are added.
Does changing quality re-encode results?
No. Completed or running files retain the quality selected when their conversion began.
Why can AVIF encoding take longer?
The WebAssembly AVIF encoder is compute-intensive. This component uses speed 8, but large images still need time and memory.
Can it convert animated WebP?
It does not preserve animation. Browser Canvas decoding produces pixels for a still frame, which are encoded as a still AVIF.
Are transparency and metadata retained?
Decoded alpha pixels can pass into AVIF, but source metadata is not copied and exact results depend on browser decoding and the encoder.
Can I batch convert files?
Yes. Files convert independently. Multiple completed results can be downloaded as webp-to-avif.zip.
Are files uploaded?
No. WebP decoding and AVIF encoding run locally in your browser.
Ready to convert your WebP files?
Set AVIF quality first, add files above and compare each completed result before downloading.