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.
X3F to ICO
Developing a .x3f camera file into .ico turns unprocessed sensor data into a finished image any app can open. Free, private, and validated — the file never leaves your browser.
Private for supported formats — processed in your browser
Runs on your deviceConvert supported files
Drop X3F files here
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.About converting Sigma RAW to Windows icon
Developing a .x3f camera file into .ico 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.
An .ico file is a Windows icon container that bundles the same artwork at several sizes and color depths so the OS can pick the best match for any context. On the web it survives as the classic favicon format, with favicon.ico still the fallback path every browser requests. For this route the practical draw is multiple resolutions in a single file, chosen automatically and understood by every browser and every version of Windows — balanced against hard 256x256 ceiling makes it useless for general imagery, which is worth knowing before you commit a large batch.
Why convert X3F to ICO?
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 .ico buys you multiple resolutions in a single file, chosen automatically, which is why it is the better fit for website favicons served from the /favicon.ico fallback path. Because the conversion runs locally, trying it costs nothing but a few seconds of compute on your own machine.
X3F vs ICO at a glance
| Aspect | Sigma RAW (.x3f) | Windows icon (.ico) |
|---|---|---|
| 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 | a directory header indexes multiple images, each with its own dimensions and bit depth |
| Strongest at | base-ISO landscape, product, and architecture work where Foveon detail shines | website favicons served from the /favicon.ico fallback path |
| Weak spot | third-party support is the weakest of any major RAW format; Sigma Photo Pro is often the only full-fidelity path | hard 256x256 ceiling makes it useless for general imagery |
Pick ICO as the output
Select .ico in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if ICO is selectable, the route is real and validated.
Convert on your device
Press Convert. A LibRaw WebAssembly decoder demosaics the sensor data in your browser and renders a developed image ready for export.
Verify and download
Each result is signature-checked before the download unlocks, so a failed encode can never masquerade as a valid ICO file. Outputs keep the original filename with the .ico extension.
X3F to ICO questions, answered
Will converting X3F to ICO lose quality?
Since x3f is lossless-oriented and ico is lossless-oriented, the conversion preserves the source content exactly as stored; no additional compression pass is applied beyond what .ico itself requires.
Is it private to convert X3F files here?
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.
Where will the ICO file work?
All browsers request and render .ico favicons, and Windows depends on the format throughout its shell. macOS and Linux open it via common image libraries but use their own native icon formats (.icns, themed PNGs), so .ico matters chiefly for Windows software and website roots.
Will the ICO file be bigger or smaller than my X3F?
It depends on the content: a directory header indexes multiple images, each with its own dimensions and bit depth. Convert one representative file first and compare before batch-processing a large set.
What happens to the metadata in my X3F file?
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.