Convert BMP to AVIF
Free online converter for BMP files. Next-generation format with the best compression ratio. Nothing to install, no watermark, and every file is deleted automatically.
Drag and drop your files
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Upload a BMP file to convert it to AVIF. Up to 3 files at once, 100 MB each.
Free · up to 3 files · 100 MB each · files deleted automatically after 1 hour.
About BMP and AVIF
BMP .bmp
Microsoft's plain bitmap. It generally stores pixels with no compression at all, which makes it simple to read and very large on disk.
Good for
- Dead simple — every pixel stored literally
- No compression artefacts of any kind
- Reliably readable by old Windows software
Trade-offs
- Enormous files, often ten times a PNG of the same image
- Effectively unusable on the web
- Transparency support is inconsistent between readers
image/bmp
AVIF .avif
A modern image format derived from the AV1 video codec. It compresses harder than JPEG or WebP at the same visual quality, and handles wide colour and high dynamic range.
Good for
- The smallest files of any format here at a given quality
- Transparency, animation, wide colour gamut and HDR
- Holds up better than JPEG at very low bitrates
Trade-offs
- Support is newest — older browsers and many desktop apps cannot open it
- Encoding is slow compared with JPEG
- Fine detail can smooth over at aggressive settings
image/avif
BMP and AVIF side by side
| BMP | AVIF | |
|---|---|---|
| Compression | Uncompressed | Lossy or lossless |
| Transparency | Limited — 32-bit variants only | Yes |
| Animation | No | Yes |
| Typically used for | Legacy Windows software, intermediate working files | Modern web delivery, bandwidth-sensitive images |
What changes when you convert BMP to AVIF
You choose how much to keep
AVIF can compress either lossily or losslessly, so the quality setting decides the outcome rather than the format. High quality stays close to the BMP you started with; lower settings trade visible detail for a much smaller file.
Encoding takes longer
AVIF comes from the AV1 video codec, and that compression is slow — noticeably slower than writing a JPEG or a PNG. The payoff is the smallest file of any format here at a comparable quality. Check your audience first: browsers handle AVIF well now, but plenty of desktop and print software still will not open it.
How the AVIF is written
Our default is quality 60 — the scale is not comparable with JPEG's, and 60 here is a visually higher setting than the number suggests. The quality control on the converter moves this if you need to — the default aims to be indistinguishable from the source at a sensible file size, rather than to win a compression benchmark.
Colour detail is stored at half resolution
AVIF keeps full brightness detail but records colour at half resolution in each direction, because the eye is far more sensitive to the first than the second. On photographs it is invisible. On saturated edges it is not: red text on white, thin coloured lines and flat graphic shapes can pick up fringing. If the BMP is a screenshot, a logo or anything with text in it, a lossless format will treat it far better.
Expect a dramatic drop in size
A BMP stores every pixel literally, with no compression at all — which is why they are so large. AVIF compresses, so the same image commonly lands somewhere between a tenth and a half of the size it started at. Nothing about the picture changes to achieve that: the file was simply storing its pixels in the least efficient way available.
Other BMP conversions
Other ways to get AVIF
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