The most efficient photo format you can use today
AVIF stores a photo as one frame of AV1 video, and it inherits that codec's ability to predict and smooth image content very cheaply. For photographs it is the best per-byte format that browsers can display: a JPG re-encoded as AVIF at a comparable visual level is commonly 40 to 60 percent smaller, and the gap over WebP is another 20 to 30 percent. Chrome, Firefox and Edge have shown it for years, and Safari since 16.4 in 2023.
This page encodes with libaom compiled to WebAssembly, inside a Web Worker, using every core the browser will give it. No upload takes place, which also means the encode time is entirely down to your machine.
Lossy on top of lossy
A JPG has already discarded detail, and AVIF discards more. The two codecs fail in different ways, which affects how the result looks. JPG leaves ringing around edges and 8x8 blocks in flat areas; AVIF smooths texture and can remove fine grain entirely. When you re-encode, AVIF actually cleans up some of the JPG's blockiness, which is why an AVIF made from a JPG often looks better than the JPG at the same file size. The trade is that skin, sand, foliage and film grain become slightly waxier. Compare at 100 percent zoom rather than trusting the number on the slider.
The slider runs from 20 to 95, default 80. AVIF quality values are not the same scale as JPG's. For most photos, 65 to 75 produces a file that looks equal to the JPG source at a fraction of the size. Push to 80 or 85 for portraits and product images where texture matters; go below 60 only for thumbnails and backgrounds where smoothing is acceptable. Skies and gradients can show faint banding at the low end because the output is 8-bit.
Worked example and timing
A 4032x3024 phone photo, 2.8 MB as JPG, typically becomes:
- around 500 to 900 KB at quality 80,
- around 350 to 600 KB at quality 65,
- around 200 to 350 KB at quality 50, with visible smoothing in textured areas.
A 1600-pixel web version of the same photo, 420 KB as JPG, usually ends up between 90 and 160 KB at quality 70. These are typical figures, not guarantees; a night shot with heavy noise compresses far less than a clean daylight scene.
Expect the encode to take noticeably longer than JPG or WebP. A 12-megapixel photo takes a few seconds on a recent laptop and can take tens of seconds on a mid-range phone. The tool processes files one after another, so a batch of twenty large photos is a coffee break, not a click.
What is removed along the way
Decoding through a canvas strips all EXIF: camera, lens, date, GPS and any copyright field. The orientation tag is applied first, so the output is physically upright. Colour profiles are applied and dropped, so a Display P3 photo is mapped to sRGB. The output is 8-bit and single-frame. It is not HDR, even if the source came from a phone that shot in HDR. Dimensions are preserved; if you need a smaller image, resize it with Resize image first, since fewer pixels save more than any codec.
When to stay with JPG or WebP
AVIF is a format for images you serve on your own website with a fallback. Almost nowhere else wants it yet: photo printing services, older Windows and macOS releases, most email clients, stock photo uploads and many CMS thumbnailers either reject it or convert it back. Social networks re-encode whatever you upload, so AVIF buys nothing there. For a safer modern format use JPG to WebP, and read WebP vs AVIF vs JPEG for a side-by-side with numbers. If you only need the file under a size limit for a form, Compress image produces a JPG that will be accepted everywhere.