Convert BMP to AVIF — Free, Fast & Private
AVIF gives one of the smallest results from an uncompressed BMP, with slower encoding and narrower app support. Everything runs in your browser — nothing is uploaded.
Lossy output from a raw source
A BMP holds every pixel, so there is little to carry over besides the picture itself, and the AVIF is a lossy encode of it. For exact pixels, use BMP to PNG.
Where AVIF opens
AVIF displays in Chrome 85+, Firefox 93+, Safari 16+ and Edge 85+. If the destination is a form or an older app, BMP to WebP is safer.
What to expect from the size
A BMP is almost uncompressed, so even a modest encoder makes it far smaller, and AVIF is among the smallest results. The measured table below shows how large the gap is on real BMPs. The more detailed the picture, the longer the encode takes.
Check the AVIF against the BMP before you save
The result card shows the BMP size, the AVIF size and the output dimensions, with a before and after slider for edge and gradient detail. Batches download as a ZIP.
Encode time
AVIF encoding takes longer than WebP or JPG, and the wait grows with the size of the image. For a batch of large BMPs where speed matters more than the last few kilobytes, WebP finishes much sooner and still opens almost everywhere.
BMP to AVIF on real files: measured sizes
| File | Before | After | Change |
|---|---|---|---|
| Phone photo (2016 × 1512), as BMP | BMP · 2016 × 1512 px · 8.72 MB | AVIF · 2016 × 1512 px · 467.0 KB | 19.1× smaller |
| Scanned signature, as BMP | BMP · 2041 × 617 px · 3.60 MB | AVIF · 2041 × 617 px · 14.7 KB | 251.1× smaller |
| Screenshot, as BMP | BMP · 1280 × 800 px · 2.93 MB | AVIF · 1280 × 800 px · 16.5 KB | 181.8× smaller |
Measured 2026-10-07 in Chromium 145.0.7632.6 by running this page's converter with its default setting (AVIF) on each file. The photos and scans are CC0 or public-domain files from Wikimedia Commons; the screenshot is MiniPx's own; each BMP is the named file saved as an uncompressed 24-bit BMP (the 12 MP phone photo was first halved to 2016 × 1512). Sizes are shown as the tool shows them (1 KB = 1,024 bytes).