AVIF is the newest widely supported image format on the web, and for photos it usually produces the smallest files of anything a browser can display. Switching hero images and galleries to AVIF can cut page weight noticeably, even compared with WebP. The catch is that encoding AVIF is slow, and no browser can save AVIF from a canvas, so most tools do the work on a server.
This converter brings its own AVIF encoder instead. It downloads once, about 3.5 MB of WebAssembly, and then converts PNG, JPG, WebP, GIF and BMP files on your device, one after another, without uploading them.
What AVIF is and who can open it
AVIF stands for AV1 Image File Format. It stores a picture using the intra-frame coding of the AV1 video codec, developed by the Alliance for Open Media, inside the same HEIF container that iPhones use for HEIC. It supports transparency, and for photos it often reaches the same visual quality as WebP at a noticeably smaller size, and JPG at around half the size, depending on the image.
Viewing AVIF works in Chrome (since version 85), Firefox (since 93), Safari 16 and later on iPhone, iPad and Mac, and Edge (since 121). Older browsers, some image viewers, email clients and editing programs still cannot open it, which is why websites usually serve AVIF with a WebP or JPG fallback through the picture element.
When AVIF is worth the extra encoding time
Large photos on a website
Hero banners, portfolio images and product galleries are where most page weight sits. Converting them to AVIF and keeping a WebP or JPG fallback gives modern browsers the lightest version.
Squeezing images under a size budget
When a page, an app bundle or an email template has a hard weight limit, AVIF often keeps more detail than JPG at the same file size, particularly in smooth skies and skin tones.
Archiving screenshots and images with transparency
AVIF keeps an alpha channel, so transparent PNG graphics convert without a white box behind them, usually at a fraction of the PNG size.
How the conversion runs
Each file is decoded by your browser inside a Web Worker and its pixels are handed to the jSquash AVIF encoder, a WebAssembly build of the open-source libavif library. The site uses the single-threaded build, because the multi-threaded one needs a browser security mode (cross-origin isolation) that this site does not enable. That makes encoding slower than desktop tools that use every CPU core: a phone photo can take several seconds, and a very large image noticeably longer.
Quality runs from 10 to 100 and starts at 60. AVIF quality numbers are not the same as JPG ones; 50 to 70 usually looks clean for photos, while 75 to 85 suits screenshots and graphics with text. Encoding effort trades time for size: Fast finishes quickest, Balanced is the default, and Smallest file spends longer searching for a more compact encoding. Each result shows the old and new size.
Cómo usar esta herramienta
- Drop PNG, JPG, WebP, GIF or BMP images on the box above, up to 50 MB each.
- Set Quality; start with 60 for photos.
- Choose an Encoding effort: Fast, Balanced or Smallest file.
- Press Convert. The encoder downloads on the first run, then files are converted one by one.
- Download each AVIF or press Download all (.zip).
Limitations
- Encoding is single-threaded and much slower than WebP or JPG. Large batches can take minutes, and an image whose conversion runs longer than 10 minutes is stopped.
- Animated GIFs become a still AVIF of the first frame.
- EXIF data such as camera details and GPS location is not carried into the AVIF file.
- Images above 100 megapixels are refused, and very large photos may run out of memory on phones.