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 AVIF
Developing a .x3f camera file into .avif turns unprocessed sensor data into a finished image any app can open. Free, private, and validated — the file never leaves your browser.
100% private for supported formats
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 AVIF image
Developing a .x3f camera file into .avif 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 .avif file stores a still image (or sequence) coded with the AV1 video codec inside a HEIF-derived container. It is currently among the most efficient image formats deployed on the web, routinely beating JPEG by half at similar quality while adding HDR, wide gamut, and alpha. For this route the practical draw is best-in-class compression among widely supported web formats and 10/12-bit HDR and wide-gamut color, which JPEG cannot represent — balanced against encoding is much slower than JPEG or WebP, especially at high effort settings, which is worth knowing before you commit a large batch.
Why convert X3F to AVIF?
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 .avif buys you best-in-class compression among widely supported web formats, which is why it is the better fit for serving hero images and photo galleries where bandwidth savings are significant. Because the conversion runs locally, trying it costs nothing but a few seconds of compute on your own machine.
X3F vs AVIF at a glance
| Aspect | Sigma RAW (.x3f) | AVIF image (.avif) |
|---|---|---|
| Format type | Lossless — every pixel or sample is preserved exactly | Lossy — discards detail it judges invisible to shrink files |
| How it stores data | records three stacked layers per photosite, exploiting silicon's wavelength-dependent light absorption instead of a color filter array | encodes AV1 intra frames; both lossy and a mathematically lossless mode are defined |
| Strongest at | base-ISO landscape, product, and architecture work where Foveon detail shines | serving hero images and photo galleries where bandwidth savings are significant |
| Weak spot | third-party support is the weakest of any major RAW format; Sigma Photo Pro is often the only full-fidelity path | encoding is much slower than JPEG or WebP, especially at high effort settings |
| Metadata | 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 | eXIF and XMP are stored as metadata items in the HEIF container alongside ICC profiles or CICP color signaling, and mainstream encoders preserve them on conversion |
Pick AVIF as the output
Select .avif in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if AVIF 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 AVIF file. Outputs keep the original filename with the .avif extension.
X3F to AVIF questions, answered
Will converting X3F to AVIF lose quality?
Some. Since x3f is lossless-oriented and avif is lossy-oriented, the encoder will discard detail it judges least visible; the quality slider controls how aggressive that is. Keep the original .x3f if you may need a pristine master later.
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 AVIF file work?
Chrome 85+ (2020), Firefox 93+ (2021), and Safari 16+ (2022) render AVIF natively, covering the overwhelming majority of current browsers. On the desktop, macOS 13+ and Windows (via the AV1 Video Extension) preview it, but plenty of older editing and printing software cannot open it yet.
Will the AVIF file be bigger or smaller than my X3F?
Smaller, usually dramatically so — that is the main reason this route exists. The quality slider trades size against fidelity; the default sits at the point where most people cannot spot the difference.
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.