Convert BMP to AVIF
Drop a BMP file below and get a AVIF back. The conversion happens on your own machine, so nothing is uploaded and there is no size or quantity limit beyond what your browser can hold in memory.
Drop images here
Accepts BMP
Lower means a smaller file. 75 is a good default for photos.
100% in your browser Files are never uploaded.
Why convert BMP to AVIF?
For the same picture, AVIF usually lands well under the size of the BMP original. That matters when you are trimming page weight or squeezing under an upload limit.
AVIF supports an alpha channel, so you can cut out a background after converting. The conversion itself will not invent transparency that the BMP file never had.
BMP vs AVIF at a glance
| Property | BMP | AVIF |
|---|---|---|
| Compression | Lossless | Lossy |
| Transparency | No | Yes |
| Typical file size | 800-1200% of an equivalent JPEG | 40-55% of an equivalent JPEG |
| Compatibility | Supported by all current browsers and most apps | All current browsers; some older desktop apps lag behind |
| Usually comes from | Older Windows software and scanners | Websites optimising page weight |
Frequently asked questions
Are my BMP files uploaded anywhere?
No. The decoder and encoder are WebAssembly modules that run inside this page. You can verify it by opening your browser’s network tab — converting a file produces no outbound requests. You could even disconnect from the internet after the page loads and it would still work.
Is there a file size or quantity limit?
There is no limit imposed by us. The practical ceiling is your device’s memory, since the image has to be held uncompressed while converting. On a typical laptop, images up to around 100 megapixels convert without trouble.
Will converting to AVIF lose quality?
AVIF is a lossy format, so some data is discarded. At the default quality setting the difference is not visible at normal viewing sizes. If you need an exact copy of the pixels, choose PNG instead.
Does it work on a phone?
Yes. The same WebAssembly modules run on mobile browsers. Conversion is slower than on a desktop because phone CPUs are weaker, and very large images are more likely to hit memory limits.
Why is my BMP file so large?
BMP stores pixels essentially uncompressed, so a single photograph can run to tens of megabytes. That alone usually makes the conversion worthwhile — expect the AVIF file to be a small fraction of the original with no visible difference.
Where does AVIF actually work?
Every major browser decodes AVIF natively, so it is safe for use on the web. Desktop applications lag further behind — plenty of image viewers and editors still cannot open it. Encoding is also noticeably slower than the other formats here, so expect a large image to take a few seconds.