BMP to AVIF converter
Drop in a BMP and get an AVIF back. BMP stores a picture as plain rows of pixels with nothing squeezed out, which makes it easy for old Windows software and simple devices to read. Your file never leaves your computer.
Need the other direction? Convert AVIF to BMP
How to convert BMP to AVIF
- 1 Drop your BMP .bmp or .dib file onto the page, or click to browse for it.
- 2 Set the quality, or leave the default, which keeps the file small without anything showing.
- 3 Convert. The work happens on your own machine, so how long it takes depends on your computer and the file.
- 4 Download the AVIF, or add more files and do the whole set in one go.
Why convert BMP to AVIF
- Best size-to-quality ratio of any widely supported still format.
- Handles transparency and very bright, very colourful photographs.
- Image CDNs serving modern browsers with a JPEG fallback.
- BMP: essentially unusable on the web because of that size.
BMP compared with AVIF
How the two formats differ on the things that decide whether a conversion is worth making.
| Property | BMP | AVIF |
|---|---|---|
| File extension | .bmp | .avif |
| Compression | Uncompressed | Lossy or lossless |
| Animation | No | Yes |
| Colour depth | 1, 4, 8, 16, 24 or 32 bits per pixel | Up to 12 bits per channel, HDR and wide gamut |
| Typical file size | Largest | Depends on mode |
| Introduced | 1986 | 2019 |
| Developed by | Microsoft | Alliance for Open Media |
| Standard | Proprietary | Open |
Quality and what changes
AVIF stores the same content under a different set of rules, so what matters here is compatibility rather than picture quality. Convert once from the best source you have rather than through a chain of intermediate files.
- One AVIF limitation to keep in mind: pushed too hard it smears fine texture rather than showing blocks.
Questions about BMP to AVIF
Is my BMP file uploaded anywhere?
No. The whole thing runs inside the browser tab you already have open. Your BMP is read straight from your own disk, converted on your machine and handed back as an AVIF. Nothing is sent anywhere, nothing is stored and there is no account.
Is there a file size limit?
There is no server-side limit because no server sees the file. The real ceiling is your device memory, since the input and the output both have to fit in the tab. A few hundred megabytes is usually fine on a desktop machine and considerably less on a phone.
Can I convert several BMP files at once?
Yes. Add as many as you like and they are processed one after another, then offered as separate AVIF downloads or as a single ZIP. Speed depends on your own processor rather than on a queue.
Does the converter work offline?
Yes, after the page has loaded once. The engine is cached by the browser, so you can disconnect, reload and keep converting. That falls out of doing the work locally rather than being a separate mode you switch on.