X3F to HEIC Converter

How to Convert X3F to HEIC Online

1. Upload Your X3F File: Drag and drop or click "+ Add Files" to select X3F captures from a Sigma SD9, SD10, SD14, SD15, SD1 Merrill, SD Quattro, DP Merrill, or dp Quattro camera. Batch upload is supported, so a whole shoot can queue at once.
2. Pick Quality Preset: Default is Very High (Recommended), which preserves the per-pixel color depth Foveon files are valued for. Drop to High or Medium for smaller files, Low for quick proofing, or open Specific file size and target an exact KB / MB cap (the encoder auto-scales quality to hit it).
3. Image Resolution (Optional): Keep the native sensor resolution, scale by Resolution Percentage, choose a Preset Resolution (4K, 1080p, 720p, etc.), or enter custom Width × Height in pixels — aspect ratio locks by default so the Foveon's 3:2 frame stays intact.
4. Convert and Download: Click Convert. Each file processes on our servers — no sign-up, no watermark, uploaded only to xconvert’s own servers, auto-deleted after a few hours.

Why Convert X3F to HEIC?

X3F is Sigma's proprietary RAW container for the Foveon X3 stacked-photodiode sensor, which records red, green, and blue at every pixel location instead of interpolating from a Bayer mosaic. The files are dense — a single Quattro capture often runs 50-70 MB — and only a narrow set of editors (SIGMA Photo Pro, recent Adobe Camera Raw, Iridient Developer, RawTherapee) can decode them. HEIC is Apple's HEIF profile, encoded with HEVC (H.265), which has been the default iPhone camera format since iOS 11 in September 2017. Converting X3F to HEIC trades raw editability for a roughly 50% smaller file at JPEG-equivalent quality, plus 10-bit color, HDR metadata, and a container that Apple Photos, Files, and AirDrop treat as native.

• Sigma archive on iPhone / iPad / Mac — Foveon shots opened on iOS land as the same HEIC type the Camera app writes, so they slot into albums, Memories, and iCloud Photos without the "?" thumbnail RAW files often show.
• Storage at ~50% of JPEG — Apple's own support page notes HEIF/HEVC "use less storage space on your devices and iCloud Photos, while preserving the same visual quality." A 60 MB X3F can land around 3-6 MB as a high-quality HEIC instead of 8-12 MB as JPEG.
• 10-bit color and HDR carry-through — Foveon files capture wide tonal range; HEIC's 10-bit channels (vs JPEG's 8-bit) hold smoother gradients in skies, skin, and night shadows that 8-bit conversion would band.
• AirDrop and Messages friendly — sharing 80 RAW files over AirDrop is glacial; the same shoot as HEIC moves in seconds and arrives viewable, not as a generic file.
• Final delivery without giving up the RAW — keep the X3F masters in your archive, ship HEIC proofs to clients on iPhones or post small previews while still holding the lossless original.
• Apple Vision Pro / spatial use — visionOS reads HEIC natively; X3F does not exist on that platform, so HEIC is the practical bridge.

X3F vs HEIC — Format Comparison

Quality Preset Guide

Frequently Asked Questions

Why convert a RAW file to HEIC instead of keeping the X3F?

You shouldn't replace the X3F — keep the original in your archive. HEIC is for delivery: phones, tablets, iCloud, messaging. X3F is only readable by SIGMA Photo Pro and a few RAW editors, so any device or person without that software sees a broken thumbnail. Converting a finished version to HEIC gives you a small, viewable, edit-tolerant copy without throwing the master away.

Will my Foveon color signature survive the conversion?

Mostly. The conversion bakes whatever white balance and tone curve the file currently has into the output, the same way an in-camera JPEG bakes its preset. The Foveon "look" — high acutance, distinctive color separation — carries through because the per-pixel RGB capture happened at the sensor; what HEIC discards is the latitude to re-grade. If you want maximum color fidelity, develop the X3F in SIGMA Photo Pro first, export 16-bit TIFF, then convert. For a direct one-step path, Very High preset and 10-bit output keep the closest match.

Why is HEIC roughly 50% smaller than JPEG at the same quality?

HEIC uses HEVC (H.265) intra-frame compression, which has more efficient block partitioning, prediction modes, and entropy coding than JPEG's 1992-era DCT. Apple documents the size advantage on its HEIF/HEVC support page. The trade-off is encoder cost (HEVC is slower to compress) and patent licensing, which is why Chrome, Firefox, and Edge still don't display HEIC natively.

Which browsers and operating systems can open my HEIC file?

Native viewers: iOS 11+ (iPhone 7 and newer), iPadOS 11+, macOS High Sierra 10.13+, Apple Vision Pro, Safari 17+ on Mac and iOS. Windows 10 and 11 open HEIC after installing Microsoft's free HEIF Image Extensions from the Store. Android 9+ devices generally display HEIC. Chrome, Firefox, and Edge do not render HEIC in <img> tags — recipients on those browsers see a download prompt. If you need cross-browser web display, convert to HEIC to JPG or to AVIF instead.

Can I batch-convert a full shoot from my SD Quattro H?

Yes. Drop the entire folder onto the upload zone; every X3F queues with the same Quality Preset and Resolution settings. The processing runs file-by-file in your session, so the only practical limit is your machine's memory and however many large RAWs you want to handle at once. Quattro H files can exceed 100 MB each, so for very large batches consider doing 20-30 at a time.

Should I downscale resolution when converting from a Quattro file?

Depends on the destination. The dp Quattro / SD Quattro produce 5424 × 3616 pixels (~20 MP effective for output), the SD1 Merrill 4800 × 3200, and the original SD9 only 2268 × 1512. For iPhone viewing, anything above 4K (3840 × 2160) is wasted — pick the 4K preset or scale by 50-70%. For print delivery, keep native. Foveon files downscale exceptionally well because every pixel already holds full RGB, so a 50% scale loses less perceived detail than the same scale on a Bayer RAW.

Why does my converted HEIC look slightly different than SIGMA Photo Pro's preview?

SIGMA Photo Pro applies its own Foveon-specific color science and tone curves that no other decoder fully replicates. A web converter uses a general-purpose RAW pipeline (typically dcraw or LibRaw) plus the HEVC encoder, so colors and contrast can shift — usually subtle, sometimes noticeable on skin and foliage. For a colorimetric match, export 16-bit TIFF from SIGMA Photo Pro and convert that TIFF to HEIC instead; you can also try X3F to JPG, X3F to TIFF, or X3F to PNG for comparison.

Will Live Photos or depth maps transfer?

No. X3F is a single still capture — Foveon cameras don't record Live Photo motion or depth-map metadata. The HEIC file you get is a single-image HEIF, not a motion-photo or portrait-mode HEIC. If you need the smallest viewable file and don't care about Apple ecosystem niceties, X3F to AVIF typically produces similar or smaller output with broader browser support.

Is the upload private?

Files process in your active browser session and are not retained after you leave the page. No account, no watermark, no email signup — the same flow whether you convert one file or eighty.