JPG to RAF Converter
Convert JPG to RAF in your browser. You download a Linear DNG (.dng), not a .raf: only a Fujifilm camera can create a genuine RAF, and every editor that opens RAF also opens DNG. Nothing is uploaded.
- Processed locally
- No upload, no wait
- No sign-up
- No watermark
Drop images here
or choose files · paste with Ctrl/⌘ V
JPG expected · other image formats also work
How to use JPG to RAF
- 1
Add your JPG files: drop them here, choose them, or paste from the clipboard.
- 2
There is nothing to tune: the DNG is written uncompressed. Resizing and rotating are under More options if you need them.
- 3
Click Convert. Each file is decoded and encoded in a background thread on this device.
- 4
Download the .dng files one at a time or together as a ZIP.
Why use Aback Images for jpg to raf
Where a RAF would go
RAF files are opened by Fujifilm X RAW Studio, Lightroom, Photoshop Camera Raw, Capture One and darktable, and every one of them opens the DNG too.
DNG next to JPG
The DNG is written uncompressed, so expect it to be several times larger than the JPG, which stores lossy DCT coding in 8×8 pixel blocks, with colour usually stored at half resolution.
No new artefacts
JPG is already lossy, since it stores lossy DCT coding in 8×8 pixel blocks, with colour usually stored at half resolution; the DNG keeps the decoded pixels uncompressed, so this step adds no compression damage of its own.
Processed on your device
Your images are decoded, edited and encoded inside this browser tab by Web Workers. Nothing is uploaded to a server.
JPG vs RAF
What changes from JPG to RAF
Encoding: the JPG uses lossy DCT coding in 8×8 pixel blocks, with colour usually stored at half resolution; RAF uses uncompressed or lossless compressed sensor data in Fujifilm's own container, and the download is a Linear DNG: demosaiced 8-bit RGB with the colour matrices raw editors need.
Bit depth: 8 bits per channel in the JPG; RAF allows 12 to 16 bits per channel depending on the camera, and the DNG written here has 8 bits per channel, linearised.
Colour: YCbCr shown as RGB, greyscale, or CMYK from print software in the JPG; RAF supports camera RGB from an X-Trans 6×6 or Bayer 2×2 mosaic, written here as 8-bit sRGB.
Metadata: the JPG can carry EXIF (camera, date, GPS), XMP, IPTC and an ICC profile in APP segments; RAF can carry EXIF and Fujifilm maker notes, including the Film Simulation, but nothing is copied across.
About JPG
JPEG is the universal photo format. It compresses by discarding fine detail the eye is least sensitive to, which makes photos small but blurs sharp edges and text if pushed too far.
A JPEG starts with the bytes FF D8 and is a run of marker segments: APP1 carries EXIF and often a thumbnail, APP2 an ICC profile, DQT the quantization tables that decide the quality, and SOS the compressed scan, which ends at FF D9.
JPG files usually come from cameras, phones, scanners and almost every app that saves photos.
About RAF
RAF is the raw format of Fujifilm cameras, from the X series to the medium-format GFX. Most X-series bodies use an X-Trans sensor with a 6×6 colour filter pattern instead of the usual Bayer 2×2.
RAF is not TIFF at the top level: it opens with the text 'FUJIFILMCCD-RAW', then a header with the camera model and offsets to three blocks: a JPEG preview near the start of the file, a header describing the sensor layout, and the sensor data.
RAF files come from Fujifilm X-T, X-H, X-S, X-E, X100 and GFX cameras.
When converting JPG to RAF makes sense
Forms and workflows that ask for RAF usually feed a raw editor, and each of those opens DNG as well, so the DNG can take the RAF's place. Keep the JPG if you only need to view or share the picture.
What RAF offers when it comes straight from the camera: Film Simulation baked into the embedded JPEG; Lossless compressed option on recent bodies; Large medium-format files from GFX cameras. Its drawbacks: Fujifilm's own container rather than TIFF; X-Trans demosaicing differs between raw editors; Film Simulations need camera-matching profiles in third-party editors.
Limitations
- JPEG artefacts already in the file, such as blocking near edges and smeared colour, are kept as pixels: a lossless target preserves them faithfully rather than removing them.
- The DNG holds the decoded 8-bit pixels, so it adds no dynamic range or detail beyond the JPG.
More conversions
Related tools
Convert RAF to JPG in your browser, made from the full-size preview your Fujifilm camera stored in the file. Batch, private, no uploads.
Convert JPG to PNG in your browser, ready for screenshots, logos, graphics and anything that needs transparency. Batch, private, no uploads.
Convert JPG to WebP in your browser, ready for images on websites and in apps. Batch, private, no uploads.
Convert JPG to AVIF in your browser, ready for maximum compression on modern websites. Batch, private, no uploads.
Convert JPG to HEIC in your browser, a HEIF file with JPEG compression inside. Batch, private, no uploads.
Convert JPG to GIF in your browser, ready for short animations and reactions that must play everywhere. Batch, private, no uploads.
Convert JPG to PDF in your browser, one PDF page per image. Batch, private, no uploads.
Convert JPG to SVG in your browser, traced into real vector paths. Batch, private, no uploads.
Frequently asked questions
Why do I get a .dng file instead of a .raf?
A real RAF is written by Fujifilm cameras and holds the sensor's own readings (12 to 16 bits per channel depending on the camera, stored as uncompressed or lossless compressed sensor data in Fujifilm's own container) along with EXIF and Fujifilm maker notes, including the Film Simulation. A JPG holds no sensor data, so no software outside the camera can create a genuine RAF. The Linear DNG you get instead is Adobe's open raw format, and every editor that opens RAF files opens it with the same raw controls. It holds decoded pixels, so it adds no quality or dynamic range.
Does converting JPG to RAF lose quality?
DNG is written uncompressed, so the pixels are stored exactly as decoded. Artefacts already in the JPG stay, but nothing new is lost.
Are my images uploaded anywhere?
No. Processing happens inside your browser with WebAssembly and Web Workers. The site only downloads the app code and codecs; your files never leave your device. You can confirm this with the live upload counter on the tool, or in your browser's network panel.
Can I process many files at once?
Yes. Drop a whole selection or folder. Files are processed in parallel on several worker threads, each result can be downloaded on its own, and everything can be saved as one ZIP.
Is it free? Is there a file limit or watermark?
It is free with no account, no watermark and no daily limit. The only limit is your device's memory: very large images (over roughly 100 megapixels) may be refused to keep the tab from crashing.