X3F to WebP Converter
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Supports: X3F
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Need help?How to Convert X3F to WebP Online
- Upload Your X3F File: Drag and drop your Sigma RAW file onto the upload area, or click "+ Add Files" to browse. Batch upload is supported, so a folder of dp Quattro or sd Quattro shots can be queued in one pass.
- Pick Quality Preset: The default is "Very High (Recommended)" which gives near-visually-lossless WebP. Drop to "High" or "Medium" for smaller files when the image will be displayed at thumbnail or hero-banner sizes. To target a specific upload limit, switch to "Specific file size" and enter a value in KB or MB.
- Resize and Toggle Lossless (Optional): Under "Image resolution," pick a preset (4320p, 2160p, 1440p, 1080p, 720p, 480p), set a "Resolution Percentage," or enter custom Width / Height with aspect ratio locked. Set "Lossless?" to Yes if you need a pixel-perfect WebP for archival or further editing; leave at No (Recommended) for web delivery where 25-34% smaller files than JPEG matter more than bit-exact pixels.
- Convert and Download: Click Convert. Files are processed on our servers — no sign-up, no watermark, and your X3F is deleted from our servers after a few hours permanently.
Why Convert X3F to WebP?
X3F is Sigma's proprietary RAW container for Foveon X3 sensor data: three stacked photodiode layers per pixel location capture red, green, and blue at the same site instead of interpolating from a Bayer mosaic. The format is gorgeous for color rendition but useless on the open web — browsers cannot decode X3F, the files are commonly 30-60 MB each, and outside Sigma Photo Pro almost no consumer tool opens them. WebP, announced by Google on September 30, 2010 and built on VP8 intra-frame coding, is the modern fix: native support in Chrome, Firefox 65+, Safari 16+, and Edge covers ~96% of global browsers per caniuse, and the file is typically 25-34% smaller than the JPEG you would otherwise post.
- Publish Foveon shots to a blog or portfolio — A 50 MB X3F from an sd Quattro H becomes a 200-400 KB WebP at "Very High" quality with the Foveon micro-contrast still visible at 2048 px wide. Squarespace, Ghost, and WordPress all serve WebP natively in 2026.
- Hit Core Web Vitals budgets — Google's PageSpeed Insights penalises hero JPEGs over ~200 KB; the same image as WebP at 75-80 quality lands well under the LCP element budget.
- Share a proof gallery with a client — Reduce 30 selects from 1.5 GB of X3F down to ~10 MB of WebP that any phone browser opens instantly, without the client needing Sigma Photo Pro.
- Feed an e-commerce CDN — Shopify, BigCommerce, and Cloudflare Images all accept WebP uploads and re-encode internally; sending WebP source avoids a double-recompression of your Foveon detail.
- Archive a working web copy alongside the RAW — Keep the X3F as the master, but generate a lossless WebP (toggle Lossless: Yes) as a reviewable proxy that compresses about 26% smaller than the equivalent PNG, per Google's published comparison.
X3F vs WebP — Format Comparison
| Property | X3F (Sigma RAW) | WebP |
|---|---|---|
| Type | Proprietary RAW container | Open web image format |
| Owner / origin | Sigma Corporation (Foveon, Inc.) | Google, released Sept 30, 2010 |
| Sensor data | Full RGB at every photosite (3 stacked layers) | Decoded 8-bit per channel RGB(A) |
| Compression | Largely uncompressed sensor data | Lossy (VP8) or lossless |
| Typical file size | 30-60 MB per shot (sd Quattro H ≈ 50 MB) | 100 KB - 2 MB at web quality |
| Max dimensions | Determined by sensor (e.g. 6192 × 4128 on sd Quattro H) | 16383 × 16383 pixels |
| Transparency | No | Yes (both lossy and lossless modes) |
| Browser support | None | ~96% global (Chrome 32+, FF 65+, Safari 16+, Edge 18+) |
| Editable in browser? | No | Yes (any modern browser, image editors) |
| Best for | Capturing and editing in Sigma Photo Pro | Web delivery, mobile, CDNs |
Sigma Cameras That Produce X3F
| Camera line | Years | Effective pixels | Notes |
|---|---|---|---|
| SD9 / SD10 | 2002 / 2003 | 2268 × 1512 × 3 layers (~3.4 MP per layer) | Original Foveon DSLRs |
| SD14 / SD15 | 2006 / 2010 | 2640 × 1760 × 3 (~4.6 MP per layer) | Bayonet mount, JPEG-capable |
| DP1 / DP2 series | 2008-2013 | Same sensor as SD14/15 then 15 MP class | Fixed-lens compacts |
| SD1 / SD1 Merrill | 2010 / 2012 | 4800 × 3200 × 3 (~15 MP per layer) | First "Merrill" generation |
| dp Quattro (dp1/2/3) | 2014 | Quattro sensor: 5424 × 3616 top layer | Top layer 1:1, lower layers 1:4 |
| sd Quattro / Quattro H | 2016 | Up to 6192 × 4128 top layer | APS-H on the H model |
| fp / fp L | 2019 / 2021 | Bayer (not Foveon) | These output DNG, not X3F |
Quality Preset Quick Guide
| Preset | Typical WebP quality factor | Best for |
|---|---|---|
| Highest / Very High | ~85-95 | Portfolio publishing, near-visually-lossless |
| High | ~75-80 | Blog posts, product galleries, social uploads |
| Medium | ~60-70 | Thumbnails, list-view tiles, email embeds |
| Low / Very Low | ~30-50 | Placeholder / preview images only |
| Lossless: Yes | n/a (lossless codec path) | Archival web proxy, edit-safe intermediate |
Frequently Asked Questions
Will I lose Foveon "color depth" by converting X3F to WebP?
You will lose the editing latitude of RAW — once committed to an 8-bit-per-channel WebP you cannot pull shadow detail back the way Sigma Photo Pro can from the original X3F. However, the visible Foveon color and micro-contrast survive a Very High or Lossless WebP conversion just fine for screen viewing. Keep the X3F as your master and treat the WebP as a publishable derivative.
Why is WebP a better web output than JPEG for my Sigma shots?
WebP lossy averages 25-34% smaller than JPEG at matching visual quality, and lossless WebP averages about 26% smaller than PNG — both numbers come directly from Google's WebP documentation. For a 15 MP Merrill or sd Quattro frame, that's the difference between a 350 KB and a 500 KB upload, which moves the needle on Largest Contentful Paint scores.
Do I need Sigma Photo Pro installed to convert X3F here?
No. The Conversion runs on our servers — you do not need Sigma Photo Pro, X3Fuse, or a Photoshop X3F plug-in installed. That is the whole point of running it through xconvert: open access to a format that otherwise needs vendor software.
Which Sigma camera models am I likely to have X3F files from?
Any Foveon-sensor Sigma: the SD9/SD10/SD14/SD15/SD1/SD1 Merrill DSLRs, the DP1/DP2/DP3 fixed-lens series, the dp Quattro line, and the sd Quattro / sd Quattro H. The 2019-and-later fp and fp L are Bayer-sensor cameras and produce DNG instead — for those use the DNG to WebP converter.
Should I enable Lossless WebP, or stick with the default lossy mode?
For social posts, blog images, and most portfolio use, leave Lossless at No — the file will be far smaller and the visual difference at normal viewing distance is negligible. Toggle Lossless to Yes when you need a pixel-exact intermediate (for example, before further editing in a web-based tool, or as an archival proxy alongside the RAW master).
What's the largest WebP I can produce from a high-res Sigma file?
WebP caps each side at 16383 pixels per the format specification, which is well beyond any Sigma sensor — even the sd Quattro H's 6192 × 4128 fits comfortably. So you can produce WebP at full sensor resolution; the practical limit is how much detail you want to ship over the wire.
Why doesn't Chrome / Safari / Firefox open my X3F directly?
X3F is a proprietary Sigma container and the raw sensor data is partly encrypted, which is why the libopenraw project flags it as a constrained format. No mainstream browser ships an X3F decoder. WebP, by contrast, is supported natively in Chrome since v17 (2012), Firefox 65 (Jan 2019), Safari 16 (Sept 2022, partial since 14), and Edge 18+ — collectively ~96% of global browsers as of 2026.
Can I batch-convert a whole shoot at once?
Yes. Drop the entire folder of X3Fs onto the upload area; each file is converted with the same quality, resolution, and lossless settings. For very large captures (dp Quattro / sd Quattro H jobs can run 50 MB per shot), break the batch into reasonable chunks so the browser doesn't spend all its memory at once.
What if I want JPG or PNG instead of WebP for older browsers?
Use X3F to JPG for the broadest compatibility (every browser since the 1990s) or X3F to PNG for lossless flat-color output. For a flexible non-RAW master that any photo editor opens, X3F to TIFF is the better choice. Already have a WebP and just want it smaller? See compress WebP.