Add your X3F file
Drop one or more .x3f files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
Developing a .x3f camera file into .bmp turns unprocessed sensor data into a finished image any app can open. Free, private, and validated — the file never leaves your browser.
Batch files can each use a different output. Nothing uploads for local conversions.
Working inputs include camera RAW, browser-local audio/video, PDF, CBZ/CBR comics, office documents, ebooks, markup, 3D models, structured text, images, and archives.Developing a .x3f camera file into .bmp turns unprocessed sensor data into a finished image any app can open. An .x3f file is a Sigma RAW photograph captured with a Foveon X3 sensor, which stacks three photodiode layers so every pixel location records red, green, and blue directly. That architecture makes .x3f fundamentally different from Bayer-pattern RAW files — there is no color mosaic to demosaic — and gives Foveon images their reputation for peculiar, film-like per-pixel sharpness.
A .bmp file is the Windows bitmap format: raw pixel rows written to disk with a small header and, in the common case, no compression at all. Its brute simplicity makes .bmp trivial to read and write from any programming language, which is why it persists in tooling, embedded systems, and quick debugging dumps. For this route the practical draw is dead-simple structure with no decoding step at all and exactly lossless — what you write is what you read — balanced against no effective compression, so files dwarf PNG equivalents of the same image, which is worth knowing before you commit a large batch.
The practical trigger for this conversion is usually a mismatch: with .x3f, third-party support is the weakest of any major RAW format; Sigma Photo Pro is often the only full-fidelity path. Switching to .bmp buys you dead-simple structure with no decoding step at all, which is why it is the better fit for quick lossless dumps from code, since a writer takes minutes to implement. Because the conversion runs locally, trying it costs nothing but a few seconds of compute on your own machine.
| Aspect | Sigma RAW (.x3f) | Bitmap image (.bmp) |
|---|---|---|
| Format type | Lossless — every pixel or sample is preserved exactly | Lossless — every pixel or sample is preserved exactly |
| How it stores data | records three stacked layers per photosite, exploiting silicon's wavelength-dependent light absorption instead of a color filter array | pixels are typically stored uncompressed; optional RLE encoding exists only for 4-bit and 8-bit palette images |
| Strongest at | base-ISO landscape, product, and architecture work where Foveon detail shines | quick lossless dumps from code, since a writer takes minutes to implement |
| Weak spot | third-party support is the weakest of any major RAW format; Sigma Photo Pro is often the only full-fidelity path | no effective compression, so files dwarf PNG equivalents of the same image |
Drop one or more .x3f files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
Select .bmp in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if BMP is selectable, the route is real and validated.
Press Convert. A LibRaw WebAssembly decoder demosaics the sensor data in your browser and renders a developed image ready for export.
Each result is signature-checked before the download unlocks, so a failed encode can never masquerade as a valid BMP file. Outputs keep the original filename with the .bmp extension.
Since x3f is lossless-oriented and bmp is lossless-oriented, the conversion preserves the source content exactly as stored; no additional compression pass is applied beyond what .bmp itself requires.
Yes — the .x3f file is processed inside your browser tab and never uploaded. A LibRaw WebAssembly decoder demosaics the sensor data in your browser and renders a developed image ready for export. Close the tab and the file is gone from memory.
Windows treats BMP as a native citizen, and macOS, Linux, and all major browsers open it without complaint. The format's problem is never support but waste: emailing or hosting uncompressed bitmaps burns bandwidth for zero benefit, so converting to PNG is almost always an upgrade.
It depends on the content: pixels are typically stored uncompressed; optional RLE encoding exists only for 4-bit and 8-bit palette images. Convert one representative file first and compare before batch-processing a large set.
In .x3f, eXIF fields and Sigma's property lists are embedded in the container, but MakerNote conventions differ enough from Bayer vendors that generic tools extract less; ExifTool provides the most complete parsing. Re-encoding through the browser pipeline does not carry embedded metadata into the output, which doubles as a privacy scrub — check the exported file if you specifically need tags preserved.