What this tool does
Upload JPG, PNG, WebP, or AVIF images and export AVIF files for modern websites. Selected file contents are processed locally in your browser when your browser supports local conversion.
Privacy behavior
Selected file contents are processed locally in your browser for supported workflows. This privacy build does not intentionally load ads, analytics, remote fonts, or third-party runtime scripts.
Supported workflow
Use the controls on this page, review the output in your browser, then copy or download the result.
When should you use AVIF?
AVIF is a modern image format built for efficient web delivery. It can produce small files while preserving detail, especially for photos and rich graphics.
Use AVIF for websites, landing pages, product images, and performance-sensitive pages where modern browser support is acceptable. Keep JPG, PNG, or WebP fallbacks for older browsers or workflows that do not support AVIF yet.
How this converter actually works
This tool has no bundled AVIF encoder of its own. It calls the browser's native canvas.toBlob('image/avif', quality), and whether that call succeeds depends entirely on whether the browser you are using ships AVIF encoding support in its Canvas implementation. On page load, the tool runs a 1x1-pixel test encode to detect this; if the browser returns a real image/avif blob, conversion is enabled, otherwise the page shows the unsupported-browser message shown above rather than falling back to a slower JavaScript encoder.
Because encoding is entirely browser-native, there is no way to expose settings the browser itself does not expose. The quality slider (30% to 95%, default 75%) maps directly to the single quality argument Canvas accepts; there is no separate control for AVIF's advanced encoder options (chroma subsampling, film grain synthesis, or multi-pass encoding) that a dedicated AVIF encoder library might offer.
Transparency is preserved by default: unlike this site's JPEG export paths, this tool does not fill the canvas with a background color before encoding, so a source image with an alpha channel keeps its transparency in the AVIF output.
Image format capability matrix
| Format | Alpha (transparency) | Animation | Lossless option | Typical use | Browser support |
|---|
| JPEG | No | No | No | Photos, broad compatibility | Universal |
| PNG | Yes (8-bit) | No (APNG extension exists, not universally used) | Always lossless | Graphics, logos, screenshots | Universal |
| GIF | Yes (1-bit only) | Yes | Lossless within a 256-color palette | Simple animation, legacy graphics | Universal |
| WebP | Yes (8-bit) | Yes | Both lossy and lossless modes | General web delivery | All current browsers |
| AVIF | Yes (8-bit) | Yes (per spec, support varies) | Both lossy and lossless modes | High-efficiency web delivery | Varies — decoding is broader than Canvas encoding |
AVIF is based on the AV1 video codec's intra-frame (still-image) coding tools. Commonly cited third-party comparisons put AVIF's file size meaningfully below a comparable-quality JPEG at typical web-photo quality levels, though the exact margin depends heavily on image content and is not a number this tool measures itself — compare your own output before replacing production assets, as the existing FAQ below already notes.
Failure modes and limits
- Browser support for encoding, not just decoding. Some browsers can display AVIF images but cannot produce them through Canvas; this tool's built-in detection step disables the convert button and shows a message in that case rather than failing silently per file.
- No dedicated AVIF settings. Because encoding is entirely delegated to the browser, there is no control over chroma subsampling, encoder speed/quality tradeoffs, or multi-pass encoding beyond the single quality slider.
- Very large images or batches. AV1-based encoding is more computationally intensive than JPEG or WebP; large images or long batches can take noticeably longer per file and use more CPU than converting the same batch to WebP.
- Mobile devices. Phones and tablets have less CPU headroom and memory; expect slower per-image conversion and keep batches smaller than on desktop.
Frequently Asked Questions
What is AVIF?
AVIF is a modern image format based on AV1 compression. It is designed to deliver high-quality images with smaller file sizes for the web.
Is AVIF smaller than WebP?
Often, yes, but not always. Results depend on the image and quality setting, so compare the output before replacing production assets.
Are my images sent to ConvertUnlimited servers?
No server-side upload endpoint is used for this AVIF conversion flow. The browser decodes and encodes images locally when AVIF encoding is supported.
Why does AVIF conversion not work in some browsers?
Some browsers can display AVIF but cannot export AVIF through Canvas yet. In that case the page shows a friendly unsupported-browser message.
Can I convert multiple images at once?
Yes. Add multiple files, convert them together, then download each AVIF file or a ZIP archive.
Does this tool use a dedicated AVIF encoder library?
No. It calls the browser's own Canvas AVIF encoder directly. Encoding quality, speed, and available options are whatever the browser itself supports; there is no bundled fallback encoder for unsupported browsers.
Does converting to AVIF keep transparency?
Yes. This tool does not fill the canvas with a background color before encoding, so an image with an alpha channel keeps its transparency in the AVIF output.
Why is AVIF conversion slower than WebP or JPEG on this site?
AV1-based still-image encoding is more computationally demanding than JPEG or WebP encoding, so larger images and longer batches typically take more time and CPU per file.
Privacy
Privacy build: This build removes ads, analytics, remote fonts, runtime CDN scripts, and file-operation telemetry. Selected files are processed in the browser using local JavaScript and browser APIs.
ConvertUnlimited does not provide a server-side upload endpoint for this AVIF conversion flow. Selected image contents are processed locally in your browser when supported.
Terms of Use
ConvertUnlimited is provided as is. You are responsible for the files you process and for checking browser compatibility before publishing AVIF images.
Trust and privacy
Files are processed locally where supported. Review the Trust Center for the processing model and the Privacy Policy for public-site privacy boundaries.