How to convert AVIF to BMP without uploading it
Every "free" online AVIF converter you've used uploads your images to a company server, converts them there, and — in several documented cases — keeps a copy or a live download link for days. For personal photos, screenshots and anything you wouldn't post publicly, that's an unnecessary risk. The safer approach is to convert the file where it already is: on your own device.
This tool does exactly that. When you drop an AVIF here, your browser:
- Decodes the AVIF natively — every modern browser includes an AVIF decoder, so there is no decoder file to download and no waiting for a library to load. Animated AVIF files decode to their first frame only.
- Reads the image's orientation data and stores the output upright, so a portrait image doesn't come back sideways. The rest of the metadata, including location, is dropped.
- Re-encodes the pixels as a raw BMP with a pure-JavaScript BMP encoder — BITMAPINFOHEADER, bottom-up rows, at the bit depth you chose. At 32-bit the AVIF alpha channel is written into every pixel; at other depths transparency is flattened onto your chosen background colour. Your original file is never modified.
What makes this converter different
The converters that top the results for this search mostly upload your files to a server (XConvert, FreeConvert and Convertio all convert server-side), and the client-side ones we found cap the output — one takes only three files at a time, another offers only 24-bit and 32-bit output. This page is the only dedicated AVIF-to-BMP page we found that combines a batch of 20 files with a ZIP download, the full bit-depth range (1/8/16/24/32-bit), Floyd–Steinberg dithering, hardware and retro destination presets, a background colour for flattened transparency, and a live network-request counter so you can verify the privacy claim yourself. It runs entirely in your browser — there is no server to upload to.
When is BMP the right choice for an AVIF?
Almost never for sharing or storage — AVIF is far smaller and PNG is lossless and smaller still. BMP earns its place when the destination demands raw pixels: legacy Windows software and GDI tooling, printer utilities, embedded firmware and machine-vision rigs that read uncompressed data, and sprite or retro-game editors that load 1-bit or 8-bit BMPs. If the program you are feeding accepts anything else, use AVIF to PNG instead and keep the smaller file.
Honest limitations
No quality recovery
AVIF throws away detail when it compresses. A BMP holds the same decoded pixels, uncompressed — it cannot put back what AVIF discarded. Blocky artefacts in the AVIF stay blocky in the BMP.
BMPs are much larger than AVIFs
Expect roughly 10–50× the size for a 24-bit BMP of a photo, and more at 32-bit. Every file shows its size multiple honestly, and the batch bar shows the total before you download anything.
Animated AVIF is first frame only
Browsers decode only the first frame of an animated AVIF for web pages. This tool converts that frame and says so plainly on the file card. BMP has no animation at all.
10/12-bit AVIF is tone-mapped to 8-bit
AVIF can store 10-bit or 12-bit colour, but the browser canvas that feeds the encoder stores 8 bits per channel, so deep-colour AVIFs are tone-mapped down to 8-bit. For most photos the difference is invisible; for smooth gradients it can show banding.
32-bit keeps alpha, other depths flatten
A 32-bit BMP writes the AVIF alpha channel, so transparency survives — the advantage over GIF. At 24-bit and below there is no alpha channel: transparent areas are flattened onto the background colour you pick.
Metadata is stripped
Camera metadata (EXIF, including location) is dropped on re-encode. The orientation is applied where the browser exposes it, so the output is stored upright. Greyscale AVIFs stay greyscale in the pixels.