X3F to WebM Converter

How to Convert X3F to WebM Online

1. Upload Your X3F Files: Drag and drop or click "+ Add Files" to load Sigma Foveon X3F RAW files from your computer. Batch is supported — drop in an entire SD-card folder and the converter ingests every X3F at once. Files process in your browser session, no upload to third-party servers.
2. Pick a Merge Strategy: Choose Merge images to stitch every uploaded X3F into a single WebM slideshow (one video out), or Video per image to render each X3F as its own short WebM clip. Merge is the right call for portfolios, contact sheets, and time-lapse sequences.
3. Set Duration, Background, and Quality (Optional): Set Duration per frame (1 to 10 seconds — default 5), pick a Background Color (default Black, used when an image doesn't fill the frame after aspect-ratio fit), and choose a Quality Preset under File Compression — pick Constant Quality with a Very High / High / Medium / Low / Very Low preset for visual-fidelity targeting, or Constraint Quality to lock a quality range. Set Video resolution to Keep original, a Fixed Resolution (custom Width × Height), or a Preset Resolution (144p through 4320p / 8K, plus social formats like 1080×1920 vertical).
4. Convert and Download: Click "Convert" and download each WebM individually or as a ZIP. No sign-up, no watermark, no email gating.

Why Convert X3F to WebM?

X3F is Sigma's proprietary RAW format, written by Foveon-sensor cameras like the SD9 (2002), SD1 Merrill, dp Quattro series (2014), and sd Quattro series (2016). It stores three vertically stacked monochrome layers from the Foveon sensor and only opens cleanly in Sigma Photo Pro, the libopenraw / dcraw toolchain, or specialty raw editors — most browsers, social platforms, and video editors cannot display it natively. WebM is Google's royalty-free container (launched May 18, 2010, Matroska-based) holding VP8 / VP9 / AV1 video and Vorbis / Opus audio. Wrapping a set of X3F stills into a WebM slideshow plays everywhere HTML5 <video> works without a plugin. Typical use cases:

• Portfolio reels on personal websites — <video autoplay loop muted playsinline> with a WebM source plays inline on Chrome, Firefox, Edge, and Safari 14.1+ desktop / 17.4+ iOS without Flash, JavaScript players, or paid hosting. Foveon shooters specifically benefit because raw galleries can't be embedded on the open web at all.
• Client review slideshows — Send wedding, portrait, or product shoots as a single self-contained WebM instead of a 30-file RAW download. Clients without Sigma Photo Pro can review on phone or laptop.
• Time-lapse from X3F sequences — Many Sigma owners shoot interval sequences for landscapes. Stitching 200 X3F frames at 1/24 second per frame produces a smooth 8-second cinematic time-lapse in a single pass.
• Smaller files than animated GIF or PNG sequences — At 720p, a VP9-encoded WebM is typically 80-95% smaller than the equivalent GIF and 99% smaller than a PNG sequence, with full 24-bit color instead of GIF's 256-color palette.
• Web-app and CMS embedding — WordPress, Ghost, Webflow, and most static-site generators accept .webm upload directly. Foveon-rendered JPGs zipped for download are clumsier than a single inline slideshow.
• Social and ad rough-cuts — Vertical 1080×1920 or square 1080×1080 presets render social-ready aspect ratios from the same source X3Fs; no need to round-trip through Premiere or DaVinci.

Need different outputs? Convert the same X3Fs to standard stills with X3F to JPG or X3F to PNG, build an H.264 slideshow with X3F to MP4, or convert standard photos with JPG to WebM and PNG to WebM.

X3F vs WebM — Format Comparison

WebM Codec & Quality Guide — Which Preset to Pick

WebM in this converter defaults to VP9 video with Vorbis audio (slideshow output is silent unless audio is supplied). Pick a Quality Preset based on where the slideshow will play:

VP9 uses CRF ("Constant Rate Factor") from 0 (lossless) to 63 (worst); lower CRF = higher quality and bigger file. AV1, when available, is roughly 30% more efficient than VP9 at equal quality but encodes 3-5× slower. Slideshow content is unusually compressible because long still frames give the encoder nearly perfect inter-frame prediction — your real-world sizes are often well below the table above.

Frequently Asked Questions

Why convert X3F to WebM instead of JPG or PNG?

Convert to JPG / PNG when you want individual stills you can re-edit or print. Convert to WebM when you want a single playable file that browsers, phones, and CMSes treat as native video. A WebM slideshow loads, autoplays, and loops inline — a JPG gallery requires a JavaScript lightbox or a manual grid. For client reviews, embedded portfolio reels, and time-lapse, WebM is the smaller, more portable output.

Will the Foveon "stacked-pixel" color advantage survive the conversion?

Partially. X3F stores three full-resolution monochrome layers (red, green, blue) captured at each photosite by the stacked Foveon sensor, which is the source of its rendering character. Converting to WebM bakes those layers into an 8-bit-per-channel RGB video frame, then re-encodes with VP9 chroma subsampling (typically YUV 4:2:0). The look survives — Foveon-style microcontrast and color separation come through clearly at high quality — but the raw-editing latitude (white-balance, exposure recovery, demosaic choice) is gone once it's a video frame. Edit the X3Fs in Sigma Photo Pro first if grading matters, then export to TIFF/JPG before stitching.

What's the right Duration per frame for different slideshow styles?

5 seconds (the default) is comfortable for portrait and landscape review — long enough to look at each image without dragging. Pick 1-2 seconds for fast-moving showreels and contact sheets, 3 seconds for typical Instagram-pace browsing, and 7-10 seconds for ambient gallery loops. For time-lapse, pick 1/24 or 1/30 second per frame so 24 or 30 X3Fs render as one second of motion, giving you cinema-rate playback.

Should I pick VP9 or AV1 for WebM?

VP9 (the default) is the safer pick in 2026: full support in Chrome 29+ (2013), Firefox 28+ (2014), Edge 79+, and Safari 14.1+ desktop / iOS 17.4+. AV1 in WebM compresses ~30% smaller at the same visual quality but is slower to encode and slightly less universal — Safari added AV1 video support only in macOS 14 Sonoma / iOS 17 on Apple Silicon, and older Android phones may software-decode it. Pick AV1 only when file size dominates (long ambient loops, mobile-data targets) and your audience runs current browsers.

How does WebM size compare to MP4 / GIF for the same slideshow?

For a 60-second 1080p slideshow with mostly still frames: VP9 WebM lands around 15-30 MB at "High" quality; H.264 MP4 (see X3F to MP4) lands around 25-50 MB at equivalent quality; an animated GIF of the same content would be 200-500 MB and capped at 256 colors with visible banding on photographs. WebM wins on size-per-quality for any slideshow longer than a few seconds. Use WebM to GIF only when you specifically need GIF playback (e.g., legacy chat clients).

Why does Safari sometimes fail to play my WebM?

Apple shipped no WebM support before Safari 14.1 (macOS Big Sur 11.3, April 29, 2021), partial support through Safari 15.6, and full desktop support from Safari 16. iOS Safari was even later — full WebM playback only arrived in iOS 17.4 (March 2024). If a 2019 iPhone or pre-Big Sur Mac is in your audience, render an MP4 fallback with X3F to MP4 and serve both via <video> with two <source> tags.

Can I add background music to the slideshow?

Not directly in this converter — the WebM output from an image-to-video pipeline is silent (no Vorbis/Opus audio track). Render the silent WebM first, then mux audio in a video editor (Shotcut, DaVinci Resolve, kdenlive all accept WebM) or with a one-line FFmpeg command (ffmpeg -i slideshow.webm -i music.opus -c copy -shortest out.webm).

Will my X3F EXIF (camera model, ISO, lens, GPS) appear in the WebM?

No — EXIF is image-file metadata and doesn't transfer into the WebM container, which uses Matroska-style tag elements instead. The WebM output is a pure video stream. If you need to preserve shoot metadata, convert to X3F to JPG (EXIF preserved) for archival alongside the WebM slideshow, or burn the metadata into a caption layer in a video editor before final render.

Is anything uploaded to your servers?

Processing happens in your browser session and files are deleted after your session ends. No account is required, there are no watermarks, no file-count limits, and no Pro tier gating the converter or hiding presets behind a paywall.