What is a .dng file?
Digital Negative · Image · Adobe · 2004
DNG is Adobe's open, documented raw photo format, built as a manufacturer-neutral alternative to each camera brand's own proprietary raw format. It stores the sensor's unprocessed data like any raw file, but because Adobe publishes the specification and a free converter, a DNG stays readable long after a closed format might not.
What is a .dng file used for?
DNG is a TIFF-based container for camera raw data, created so raw photos would not be locked to a manufacturer's private, undocumented format such as Canon's CR2 or Nikon's NEF.
Adobe publishes the full DNG specification and gives away the DNG Converter, which turns a manufacturer's raw file into DNG without changing the underlying image data, which is why archives and libraries favour it for long-term storage.
A handful of cameras and phones, including some from Pentax and Leica and Google's Pixel line, save DNG directly instead of a manufacturer-specific raw format.
Like any raw file, a DNG is not a finished photo until it is developed in software that applies white balance, sharpening and colour, which is why it needs a raw-capable editor rather than an ordinary photo viewer.
What opens a .dng file?
The .dng format opens in the following apps, grouped by operating system. If one app does not work, try another from the same list.
Windows
- Lightroom
- Adobe DNG Converter
- darktable
macOS
- Photos
- Lightroom
- Preview
- Capture One
Linux
- darktable
- RawTherapee
Web
- Convert to JPG or TIFF first
Open a .dng file step by step
- Confirm the file really is a .dng. Drop it into the WhatFileType identifier, which reads its signature in your browser without uploading anything.
- On Windows, open it with Lightroom or Adobe DNG Converter.
- On Mac, use Photos or Lightroom.
- On Linux, try darktable or RawTherapee.
- Still stuck? Convert the .dng to JPG, which opens more widely.
Why can't I open my .dng file?
Almost always because no installed app understands DNG. Install one of the apps above, or convert the file to a format your existing software already reads. If double-clicking opens the wrong program instead of nothing at all, the file association is set to the wrong app rather than the file being broken.
The other possibility is that the file is not really a .dng at all. Drop it into the file identifier to check it by its bytes instead of its name. Nothing is uploaded.
How to convert a .dng file
You can convert a .dng file to JPG, TIFF, PNG using a conversion tool or the export menu of an app that opens it.
What is the .dng file signature (magic bytes)?
A .dng file starts with the hex bytes 49 49 2A 00, which read as II*. in ASCII. Other formats open with the same bytes, so they narrow a file down without proving it is DNG. Programs confirm the format from the tags and structure that follow the header, not from these bytes alone.
These are the documented signatures for DNG. For a full breakdown, see the TIFF file signature page.
| Hex signature | Offset | ASCII | Note |
|---|---|---|---|
| 49 49 2A 00 | 0 | II*. | little-endian TIFF-based (most DNG files) |
| 4D 4D 00 2A | 0 | MM.* | big-endian TIFF-based |
See the full magic-numbers reference for every format.
Frequently asked questions
What is a .dng file?
DNG is Adobe's open, documented raw photo format, built as a manufacturer-neutral alternative to each camera brand's own proprietary raw format. It stores the sensor's unprocessed data like any raw file, but because Adobe publishes the specification and a free converter, a DNG stays readable long after a closed format might not.
Should I shoot in DNG instead of my camera's own raw format?
If your camera offers it, DNG has the advantage of being an open, Adobe-published standard rather than a manufacturer's private format, which helps long-term compatibility. Otherwise, Adobe's free DNG Converter can turn existing raw files like CR2 or NEF into DNG at any time without losing image data.
Why won't my DNG open in an older program?
The DNG specification has had several revisions since 2004, and an old app may not understand a newer DNG's compression or features. Update the software, or re-export the file as an older DNG version using Adobe's free DNG Converter.
Related formats
Sources
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