BMP to AVIF Converter - Convert BMP to AVIF Online Free

How to convert BMP to AVIF

Add your BMP files. Drop up to 50 BMP or DIB images into the box, or browse for them. Your browser reads them first, so every BMP variant works.
Set the quality. Drag the slider - 80 is the default and still far smaller than a JPG. The page tells you whether your browser or our server will encode.
Adjust if you like. Keep or fill transparency, resize, rename the files, or pick encoder speed and full colour for server encodes.
Convert and download. Press Convert to AVIF. One or two files download directly, more than two come as a ZIP.

Want to check the result? The AVIF Analyzer shows its size, bit depth and colour layout.

Why convert BMP to AVIF?

A BMP stores every pixel raw, so a 1920 x 1080 screenshot weighs about 6 MB.

As an AVIF it is often 50-150 KB.

AVIF is the newest image format on the web, based on the AV1 video codec. It beats JPG and WebP on size at the same quality and keeps transparency, so pages load faster.

BMP vs AVIF

	BMP	AVIF
Compression	None (or simple RLE)	AV1, lossy
Typical size (1920 x 1080)	About 6 MB	50-150 KB
Transparency	Only 32-bit, patchy support	Yes, full alpha
Opens in	Windows apps, Paint	Chrome, Edge, Firefox, Safari 16+, Windows 11
Best for	Legacy software, raw pixels	Websites, fast-loading images

Need wider support? BMP to WebP is nearly as small and opens almost everywhere. For Apple photo libraries try BMP to HEIC.

In your browser or on our server?

When your browser can write AVIF itself, the whole job happens on your device and nothing is uploaded.

Chrome and Edge cannot write AVIF yet. In that case the decoded image goes to our server as a lossless PNG over HTTPS, ImageMagick encodes the AVIF, and the file is deleted the moment it is downloaded. Leftovers are swept within a few hours.

The page says which path it will use before you convert, and the result line says which one ran.

Tips for great AVIF files

Photos? Quality 60-80 is plenty - AVIF stays clean where JPG would show blocks.
Screenshots, text or logos? On the server path, turn on Full colour (4:4:4) so coloured edges stay crisp.
Websites? Pick Max width 1920 px under Resize - bigger rarely helps on screen.
Need lossless? AVIF here is lossy. Use BMP to PNG to keep every pixel.

Curious about the source first? The BMP Analyzer shows every header field.

Frequently Asked Questions

Drop your BMP files into the box, keep quality 80 or pick a preset, and press Convert to AVIF.

One file downloads as an AVIF, more than two come as a ZIP.

Only if your browser cannot write AVIF itself, which today includes Chrome and Edge. Then the image is sent as a PNG over HTTPS, converted and deleted as soon as you download it. The page tells you which path it uses before you convert.

AVIF is lossy, but at quality 70-80 the difference is very hard to see. For pixel-exact copies use BMP to PNG.

Usually 97-99% smaller. A 6 MB screenshot often becomes 50-150 KB.

The size is measured from the real AVIF, never estimated.

Yes. The alpha channel of a 32-bit BMP is kept. Pick Fill background for a solid colour instead.

Chrome, Edge, Firefox, Opera and Safari 16 or newer all show AVIF, as do Windows 11 and recent Android phones.

1, 4, 8, 16, 24 and 32-bit BMP and DIB files, uncompressed or RLE4/RLE8, with bitfields, V4/V5 headers, top-down rows and OS/2 headers.

Yes - use AVIF to BMP. Because AVIF is lossy, the round trip will not give back the exact original pixels.