X3F to AVIF Converter

How to Convert X3F to AVIF Online

1. Upload Your X3F File: Drag and drop or click "+ Add Files" to select Sigma Foveon RAWs from your SD9, SD10, SD14, SD15, SD1 Merrill, DP Merrill, dp Quattro, or sd Quattro camera. Batch uploads are supported.
2. Pick Quality Preset: Default is Very High (Recommended). Choose Highest for archival or print, High for everyday web display, Medium for fast previews, or set a Specific file size target (KB or MB) when you need to fit a CMS upload cap.
3. Set Resolution (Optional): Keep original, scale by Resolution Percentage, pick a Preset (4320p / 2160p / 1440p / 1080p / 720p), or enter custom Width x Height. Aspect ratio is preserved when you set only width or only height.
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.

Why Convert X3F to AVIF?

X3F is Sigma's proprietary RAW container for Foveon X3 sensors, which capture full red, green, and blue at every photosite by stacking three photodiodes vertically instead of using a Bayer color filter (Foveon, Inc., now owned by Sigma). The format is rich but heavy — a single sd Quattro H file can exceed 50 MB — and outside Sigma Photo Pro, Adobe Camera Raw, or libopenraw, almost nothing opens it natively. AVIF (AV1 Image File Format, AOMedia v1.0.0 released February 2019) is the modern destination: roughly half the size of JPEG at equivalent visual quality, 10/12-bit color, HDR via BT.2100 PQ/HLG, and native rendering in every current desktop and mobile browser.

• Share Foveon detail without Sigma Photo Pro — Recipients on Chrome 85+, Firefox 93+, Safari 16.4+, or Edge 121+ can view your image in any tab, no codec install needed. As of 2026, AVIF reaches roughly 94% of global web users per Can I Use.
• Cut storage on Quattro archives — Quattro H files (45 effective MP, 51 MP Bayer-equivalent output) compress dramatically to AVIF while keeping the smooth tonal transitions Foveon is known for, freeing space on small SSDs and cloud tiers.
• Faster page loads for portfolios — Substituting AVIF for JPEG hero images typically cuts payload 30-50% at matching SSIM, which improves Core Web Vitals (LCP) — Google explicitly recommends AVIF in PageSpeed Insights.
• Preserve 10/12-bit gradients — Foveon's per-site full RGB acquisition produces extremely clean skin tones and skies. Saving to 8-bit JPEG crushes those gradients; AVIF's 10- or 12-bit support keeps them intact.
• HDR-ready output — If you graded your X3F in 16-bit TIFF for an HDR display, AVIF with PQ or HLG transfer carries the wider dynamic range through to compatible browsers and TVs.
• Stop the "encrypted RAW" friction — X3F's raw payload is obfuscated and many libraries can't read newer dp Quattro files. AVIF is a plain bitstream readable by any compliant decoder, so collaborators don't need Sigma's plug-in just to look at your shot.

X3F vs AVIF — Format Comparison

Quality Preset Quick Guide

Use the Specific file size option when you need a hard cap (e.g., a 500 KB CMS limit). The encoder will iterate to land within the target.

Frequently Asked Questions

Why is my X3F file so large compared to a Bayer RAW of similar megapixels?

Foveon sensors record full red, green, and blue at every photosite via three stacked photodiodes, so a 15 MP Sigma SD1 Merrill file effectively stores 45 million color samples instead of the ~15 million a Bayer sensor records before demosaic. That triple data plus minimal RAW compression is why a single sd Quattro H frame can run 50+ MB. AVIF discards what your eye cannot perceive and routinely compresses the same image into the 1-2 MB range with no visible difference at normal viewing distances.

Will the Foveon "look" survive the conversion to AVIF?

For viewing, yes — at the Very High or Highest preset, AVIF 10-bit preserves the smooth color transitions and resolved fine detail that make Foveon distinctive. What you lose is the ability to re-develop the file (white balance, exposure recovery, demosaic algorithm choice). If you still want to edit, keep the X3F as your master and treat AVIF as the delivery export. See X3F to TIFF for a 16-bit editable intermediate.

Does this converter work with dp Quattro and sd Quattro files?

Yes. We handle the older SD9/SD10/SD14/SD15 X3F variants and the newer Quattro architecture (where the top layer carries 4x the resolution of the lower two). The Sigma X3F plug-in for Photoshop is otherwise the only way to open Quattro files in Adobe — you can skip that step entirely if you only need a deliverable image.

What quality preset should I pick for a photography portfolio?

Very High is the sweet spot — it typically compresses a 20 MB X3F to under 1.5 MB with no perceptible artifacts on retina displays, and it preserves the subtle tonal gradations Foveon owners care about. Step up to Highest only for files you'll zoom into (large prints, pixel-peep reviews). Drop to High or Medium for thumbnail grids or above-the-fold hero images where load time matters more than 100% pixel fidelity.

Can I get 10-bit or 12-bit AVIF output from my X3F?

The encoder writes 10-bit AVIF by default when the source is high-bit-depth RAW, which is the right call for Foveon — 12-bit sensor data downsampled to 8-bit JPEG visibly bands in skies and skin. Browsers that don't yet handle 10-bit AVIF (a small minority) downconvert gracefully on display.

Why convert to AVIF instead of WebP or JPEG?

At matched visual quality, AVIF files are typically 20-30% smaller than WebP and 40-50% smaller than JPEG (Netflix and Cloudinary studies). AVIF also supports 10/12-bit color, HDR (PQ and HLG transfer functions per BT.2100), and lossless mode — none of which JPEG offers. WebP is still useful when you need Internet Explorer (which AVIF dropped entirely) or pre-2022 Safari support; otherwise AVIF wins on every axis. If you want JPEG for legacy compatibility, see X3F to JPG.

My X3F came from an older SD9 / SD10 — will it still work?

Yes. The format has been remarkably stable since its 2002 debut on the SD9 — header layout and Foveon raw sensor data block are similar across the Sigma lineup, with format variations introduced for DP1 (2008) and the Quattro architecture (2014). The converter recognizes all common variants.

Will EXIF metadata (camera model, ISO, lens, GPS) transfer?

Standard EXIF (make, model, focal length, shutter, ISO, GPS if your camera tagged it) is preserved into the AVIF output. Sigma-specific MakerNotes (X3 Fill Light, Foveon-specific white balance presets) may not survive since AVIF metadata containers don't carry vendor-proprietary RAW blocks — keep the original X3F if you need round-trip editing in Sigma Photo Pro later.

How does this compare to converting via Sigma Photo Pro or Adobe Camera Raw?

Sigma Photo Pro and Adobe Camera Raw are full RAW developers — they demosaic, apply tone curves, and let you edit exposure / white balance / sharpening before export. This tool is for the "I already like the image as-shot, just give me a web-ready file" case. For creative edits, develop in Sigma Photo Pro to 16-bit TIFF first, then drop that into a JPG to AVIF or PNG to AVIF conversion. If you only need the AVIF to be smaller, Compress AVIF trims further.