ARW to BMP Converter
Convert ARW to BMP in your browser. The full-size JPEG Sony stores in the file is what gets converted, so the sensor coding never reaches the output. No raw development happens here. You get an uncompressed 24-bit BMP, or 32-bit with alpha when the image has transparency. Nothing is uploaded.
- Processed locally
- No upload, no wait
- No sign-up
- No watermark
Drop images here
or choose files · paste with Ctrl/⌘ V
RAW expected · other image formats also work
How to use ARW to BMP
- 1
Add your ARW files: drop them here, choose them, or paste from the clipboard.
- 2
There is nothing to tune: the BMP is written uncompressed. Resizing and rotating are under More options if you need them.
- 3
Click Convert. Each file is decoded and encoded in a background thread on this device.
- 4
Download the .bmp files one at a time or together as a ZIP.
Why use Aback Images for arw to bmp
Where the BMP goes next
BMP opens in every operating system and browser.
BMP next to ARW
The BMP stores the camera preview's pixels uncompressed, so it can be as large as the 25 to 80 MB raw file, or larger, depending on the preview's resolution.
No new artefacts
The preview inside the ARW is a camera JPEG; the BMP stores its decoded pixels uncompressed, so this step adds no compression damage of its own.
Processed on your device
Your images are decoded, edited and encoded inside this browser tab by Web Workers. Nothing is uploaded to a server.
ARW vs BMP
What changes from ARW to BMP
Encoding: the ARW uses Sony's lossy compressed raw, uncompressed (since the A7R II) or lossless compressed (since the A1); BMP uses usually none; RLE for some 4 and 8-bit files, and the download is an uncompressed 24-bit BMP, or 32-bit with alpha when the image has transparency.
Bit depth: 12 or 14 bits per channel in the ARW; BMP allows 1, 4, 8, 16, 24 or 32 bits per pixel, and the BMP written here has 24 or 32 bits per pixel. The sensor's 12 or 14 bits are not used: the 8-bit camera preview is converted.
Colour: camera RGB from a Bayer mosaic in the ARW; BMP supports RGB or an indexed palette, written here as 8-bit sRGB.
Metadata: the ARW can carry EXIF, Sony maker notes, a thumbnail and a full-size JPEG; BMP can carry nothing beyond the header's resolution fields (and a colour profile in rare V5 headers), but nothing is copied across.
About ARW
ARW is the raw format of Sony Alpha, RX and Cyber-shot cameras. It stores the sensor data (compressed, uncompressed or lossless compressed, depending on the model) with a full-size JPEG preview.
ARW is TIFF-based: the first directory carries EXIF and Sony's JPEG preview and the sensor data sits in a sub-directory. In Sony's classic compressed raw each block of 16 same-colour pixels keeps an 11-bit maximum and minimum plus 7-bit steps for the rest, which can leave artefacts beside high-contrast edges.
ARW files usually come from Sony Alpha mirrorless and SLT cameras, RX compacts and some Cyber-shot models.
About BMP
BMP stores raw, uncompressed pixels. Files are huge but trivially simple, which is why some legacy Windows software, embedded displays and printers still ask for it.
A BMP is a 14-byte file header ('BM' and the offset to the pixels), a DIB header (40 bytes, or 108 and 124 bytes in the V4 and V5 versions that add colour masks and alpha), an optional palette, then pixel rows padded to 4 bytes and normally stored bottom-up.
When converting ARW to BMP makes sense
BMP is the better choice for legacy software and embedded systems that require it, while ARW suits editing Sony photos in a raw developer.
BMP strengths: No compression artifacts; Read by very old and very simple software. Drawbacks to weigh: Enormous files; Poor support for transparency; No metadata.
Limitations
- Creative Look or Picture Profile settings are baked into that preview; a raw editor can start again from neutral.
- A BMP is uncompressed, about 3 bytes per pixel, or 4 with transparency, so expect a large file.
- Some older programs ignore the alpha channel of a 32-bit BMP and show transparent areas as black or white.
More conversions
Related tools
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Convert ARW to JPG in your browser, made from the full-size preview your Sony camera stored in the file. Batch, private, no uploads.
Shrink JPG, PNG, WebP, AVIF and GIF files with MozJPEG, OxiPNG and modern codecs, with a live before/after preview.
Resize to exact pixels, a percentage or a longest side, with Lanczos3 and Magic Kernel resampling. Batch ready.
Strip EXIF, GPS, XMP, IPTC and comments losslessly. Pixels are never re-encoded for JPG, PNG and WebP.
Convert between 34 image formats in bulk: HEIC, WebP, AVIF, JPEG XL, PNG, JPG, GIF, TIFF, SVG, ICO, PSD, RAW and more.
Frequently asked questions
Does converting ARW to BMP lose quality?
BMP is written uncompressed, so the pixels are stored exactly as decoded. Those pixels come from the camera's JPEG preview, so its compression stays, but nothing new is lost. The sensor's 12 or 14 bits are not used: the 8-bit camera preview is converted.
Which apps open BMP files?
Every operating system and browser.
Are my images uploaded anywhere?
No. Processing happens inside your browser with WebAssembly and Web Workers. The site only downloads the app code and codecs; your files never leave your device. You can confirm this with the live upload counter on the tool, or in your browser's network panel.
Can I process many files at once?
Yes. Drop a whole selection or folder. Files are processed in parallel on several worker threads, each result can be downloaded on its own, and everything can be saved as one ZIP.
Is it free? Is there a file limit or watermark?
It is free with no account, no watermark and no daily limit. The only limit is your device's memory: very large images (over roughly 100 megapixels) may be refused to keep the tab from crashing.