X3F Converter

How to Convert X3F to Any Format

1. Upload Your X3F File: Drag and drop your Sigma RAW or click "Add Files". The converter reads the .x3f files written by Sigma SD and DP cameras. Batch is supported — drop in a whole card's worth of frames and each one is decoded and converted in parallel.
2. Pick an Output Format and Quality Preset: Open Image File Extension and choose your target — JPG, PNG, TIFF, WEBP, BMP, AVIF, HEIC, PPM, GIF, and more. The default Quality Preset is "Very High (Recommended)"; switch to Specific file size to cap output at an exact MB target, or Image Quality (%) to set a JPEG/WEBP quality value directly.
3. Set Resolution, Bit Depth, or DPI (Optional): Under Image resolution keep the original, scale by Resolution Percentage, or pick a Preset Resolution. For archival work choose TIFF, set Lossless? to Yes, and raise Bit Depth to 16-bit to keep the Foveon tonal range; the Conversion Quality (DPI) control tags the output for print.
4. Convert and Download: Click Convert. Files are uploaded over an encrypted connection, processed on our servers, and deleted automatically after a few hours — no sign-up, no watermark, never shared.

Popular X3F Conversions

• X3F to JPG — share or print a finished photo that opens anywhere
• X3F to PNG — lossless export for editing or web graphics
• X3F to TIFF — 16-bit archival master that keeps the full tonal range
• X3F to WEBP — small, modern web image at high quality
• X3F to PDF — drop a Sigma frame into a document or contact sheet
• X3F to BMP — uncompressed bitmap for legacy Windows tools
• X3F to HEIC — efficient Apple-ecosystem photo format
• X3F to AVIF — next-gen format with the smallest files at a given quality

Why Convert an X3F File?

X3F is Sigma's proprietary RAW format, written by cameras that use the Foveon X3 direct image sensor. Foveon Inc. was founded in 1997 (a National Semiconductor / Synaptics spin-off co-founded by Carver Mead) and the X3 sensor first shipped in 2002 inside the Sigma SD9; Sigma acquired Foveon outright in November 2008. What makes the format unusual is the sensor itself: instead of a Bayer mosaic that puts one color filter over each photosite and interpolates the missing two, the X3 sensor stacks three photodiodes vertically at every pixel and reads red, green, and blue at the same location. That means no demosaicing, and in practice less risk of moiré and false color in fine detail.

That distinctive capture is exactly why an X3F is rarely the file you hand off. It is a sensor dump, not a picture — it carries the raw photodiode data plus embedded metadata (EXIF, white balance, a JPEG preview), and the image data is wrapped in Sigma's own structure rather than a standard TIFF. The practical reasons people convert:

• Compatibility. X3F is one of the least widely supported RAW formats — far less common than Canon CR2 or Nikon NEF. Many viewers, web platforms, and phones will not open it. Converting to JPG, PNG, or HEIC produces a file that displays everywhere.
• Editing and archival. A 16-bit X3F to TIFF export gives you a lossless master with the Foveon tonal range intact for retouching or long-term storage. JPG or WEBP are better when size matters more than headroom.
• Sharing and delivery. Email, messaging apps, and most websites expect a standard image. A JPG or WEBP export is a fraction of the size of the RAW and opens instantly for the recipient.
• Print and documents. Exporting to a high-DPI TIFF or X3F to PDF drops a Sigma frame straight into a layout or a print queue.

X3F at a Glance

Frequently Asked Questions

What opens an X3F file?

Sigma's own free Sigma Photo Pro is the reference application and gives the most faithful Foveon color rendering, since it knows the sensor's color science. Beyond that, open-source RAW engines LibRaw, dcraw, and RawTherapee can decode X3F, and several editors (such as recent versions of Corel PaintShop Pro) read it. Support is patchy compared with mainstream RAW formats, which is the usual reason people convert X3F to a standard image first — a JPG or PNG opens in any viewer, browser, or phone without special software.

Will I lose the Foveon color quality when I convert X3F to JPG?

You keep the rendered look but lose RAW editing headroom. Converting bakes the demosaic-free Foveon capture into a finished image, so the per-pixel color and lack of moiré are preserved in what you see. What you give up is the latitude to recover highlights, re-balance white balance, or push exposure later — that flexibility lives in the RAW data. If you want a future-proof master, export X3F to TIFF at 16-bit and Lossless? set to Yes; use JPG or WEBP only for the shareable copy.

Why is X3F so hard to open compared with other RAW formats?

X3F is proprietary to Sigma and far less common than Canon CR2 or Nikon NEF, so fewer applications bothered to support it. The format also wraps its sensor data in Sigma's own structure rather than a standard TIFF container, and the RAW payload is obfuscated, which slowed third-party decoders. Open-source projects like dcraw and LibRaw reverse-engineered support over time, but many lightweight viewers and web tools still can't preview an X3F — converting to a standard format sidesteps the whole problem.

What is the best format to convert X3F to for archiving?

A 16-bit TIFF. In our testing, exporting an X3F to TIFF with Bit Depth set to 16-bit and Lossless? set to Yes preserves the full tonal range from the Foveon capture with no compression artifacts, which is what you want for a long-term master or further retouching. The tradeoff is size — a 16-bit TIFF is large. For everyday sharing keep a parallel JPG or WEBP copy, and reserve the TIFF as the archival original.

Does the Foveon Quattro sensor change anything about conversion?

Not for you. The later "Quattro" Foveon design changed how the layers are weighted — the top layer captures most of the luminance/detail (roughly 20 megapixels) while the two lower layers record color at about a quarter of that resolution — but the resulting file is still an X3F. The converter decodes both the classic and Quattro X3F variants the same way and outputs a normal raster image; you don't need to pick a sensor type.

Can I convert several X3F files at once?

Yes. Drop a whole batch onto the page and each X3F is decoded and converted independently, then offered as individual downloads or a single ZIP. This is the fastest way to turn a card full of Sigma RAWs into share-ready JPGs or archival TIFFs in one pass. The realistic limit is total upload size and your connection speed rather than a fixed file count, since decoding runs on our servers.

Are my uploaded X3F files kept private?

Yes. Files are uploaded over an encrypted (TLS) connection, processed on our servers, and deleted automatically after a few hours. There's no sign-up, no watermark on the output, and files are never shared or made public. Because RAW files are large, the main thing to plan for is upload time on a slow connection — not a storage limit.