Full RAW conversion or the preview inside the DNG?
A DNG holds the sensor data and usually a JPG preview. The two modes give you one or the other:
- Full RAW conversion decodes the RAW image data with LibRaw at full resolution, using the white balance the device recorded, in sRGB. It took 1.5 to 10 seconds per photo in our tests.
- Camera’s embedded JPG saves the preview stored in the file, in a fraction of a second. The DNG specification makes previews optional and leaves their size to whatever wrote the file, so they range from full size to under 1,000 pixels wide.
What we measured with this page (quality 92, full size; sizes as the converter shows them, where 1 MB is 1,048,576 bytes):
| Sample DNG | File | Full RAW conversion | Time | Embedded JPG |
|---|---|---|---|---|
| iPhone 12 Pro, ProRAW | 27.8 MB | 3,024 × 4,032 px, 2.7 MB | 1.9 s | 3,024 × 4,032 px, 4.0 MB |
| iPhone XS (ProCamera app) | 9.8 MB | 4,032 × 3,024 px, 2.3 MB | 2.2 s | 852 × 640 px, 217.6 KB |
| Google Pixel 8 Pro (50 MP) | 43.0 MB | 8,160 × 6,144 px, 3.8 MB | 10.0 s | 2,560 × 1,928 px, 720.0 KB |
| Samsung Galaxy S23 Ultra | 29.9 MB | 3,648 × 2,736 px, 2.6 MB | 1.5 s | 3,648 × 2,736 px, 3.7 MB |
| DJI drone (camera FC7303) | 23.4 MB | 4,000 × 3,000 px, 2.8 MB | 2.1 s | 960 × 720 px, 346.0 KB |
| Leica Q2 (47 MP) | 83.2 MB | 8,392 × 5,632 px, 9.6 MB | 8.7 s | 8,368 × 5,584 px, 3.7 MB |
| Ricoh GR III | 31.8 MB | 6,020 × 4,024 px, 6.2 MB | 4.4 s | 6,000 × 4,000 px, 2.8 MB |
| Canon EOS 5D Mark III, lossy DNG from Adobe DNG Converter 9.8, full-size preview | 5.9 MB | 5,760 × 3,840 px, 2.5 MB | 1.9 s | 5,760 × 3,840 px, 1.2 MB |
So from the cameras, the ProRAW file and the Galaxy we tested, the embedded JPG was full size and the quickest way to get the device’s own picture; from the iPhone XS app, the Pixel and the DJI drone it was a small preview, and the full RAW conversion is the one to use. The preview’s size is chosen by whatever wrote the file — Adobe DNG Converter, for example, defaults to a medium preview. Timings are from a desktop PC only.
What a DNG file is
DNG (Digital Negative) is the RAW format Adobe published in September 2004 for any maker to use. It is an extension of TIFF 6.0; the current specification is version 1.7.1.0 (September 2023), and since March 2026 it is also an ISO standard, ISO 12234-4. Cameras from Leica, Pentax and Ricoh save it directly, Apple’s ProRAW and Samsung’s Expert RAW are DNG, Android’s camera interface writes it, DJI drones such as the Mini 4 Pro save it, and Adobe DNG Converter turns other RAW files into it.
Unlike Canon’s CR3 or Sony’s ARW, a DNG describes itself: the specification says software “do[es] not need camera-specific knowledge to decode and process files created by a camera that supports DNG”, and every colour DNG must carry its own colour matrix. In principle that lets a DNG reader handle a new phone or camera without an update. One of our samples, from an iPhone XS, came from a device that is not on LibRaw’s camera list, and it converted with natural colours like the rest.
Which DNG files work
| Kind of DNG | Where it comes from | On this page |
|---|---|---|
| Mosaic (raw sensor data), lossless or uncompressed | Cameras, drones, many phones, Adobe DNG Converter’s default | Converted: Leica, Pentax, Ricoh, DJI, iPhone XS, Pixel 8 Pro and a lossless DNG Converter sample |
| Linear (already demosaiced) | Apple ProRAW (“Linear DNG”), Samsung Expert RAW (“Linear DNG 16-bit”) | Converted: an iPhone 12 Pro ProRAW file and a 12-bit linear Galaxy S23 Ultra file (not shown to be Expert RAW) |
| Lossy (8-bit JPEG inside) | Adobe DNG Converter’s lossy option, proxies (with its JPEG XL option, the next row instead) | Converted: a DNG Converter 9.8 sample |
| JPEG XL compressed (DNG 1.7) | Adobe DNG Converter’s JPEG XL option; photographers on forums report it in recent iPhone ProRAW and Samsung Expert RAW files | Not supported: this decoder build has no JPEG XL decoder. The tool checks for it and says so (tested on synthetic files); try the embedded JPG |
| Deflate compressed | Some editors’ DNG output | Not expected to work: this decoder build appears to lack the Deflate decompression LibRaw needs for them |
Convert DNG to JPG without losing quality: what is kept and what is not
No DNG to JPG conversion is lossless. Most DNGs keep more than a JPG can — Samsung’s Expert RAW, for example, writes 16-bit files — while a standard baseline JPG holds 8-bit samples (ITU-T T.81), and JPG compression discards fine detail. What the converter keeps:
- the full pixel dimensions (unless you choose Half or Web size);
- quality 92 by default, which you can raise or lower;
- the camera details: make, model, lens, date and time, exposure, aperture, ISO and focal length are copied into the JPG’s Exif, with the photographer’s name and copyright if the device recorded them;
- sRGB for the full RAW conversion. The embedded JPG keeps its own colour (an iPhone’s Display P3 profile, for example) when saved as it is; when it has to be turned upright or resized, a JPG with a colour profile is converted to sRGB.
GPS location and the device’s serial number are left out unless you tick Include GPS location and camera serial number — worth knowing for phone and drone photos, which usually carry a location. Keep the DNG files: they hold the editing range a JPG cannot. Your DNG is only read, never changed.
Why the JPG may not look like your phone’s photo
A phone’s own JPG is heavily processed; the full RAW conversion here applies the white balance the file recorded and LibRaw’s automatic brightness, nothing more. In our tests the Pixel, iPhone XS and DJI conversions came out darker and flatter than the devices’ own pictures. Apple warns that a ProRAW photo opened in an app that does not support it “might look different than expected”.
Some DNGs also carry processing steps for the reader to apply, which the specification calls opcode lists — “such as lens corrections”. LibRaw applies them only when built with Adobe’s DNG SDK, which this build is not. So in our tests the DJI drone’s frame came out wider and with its lens distortion uncorrected, and the Leica Q2’s and Pixel’s corners came out darker than in their own JPGs. For the device’s own look, choose Camera’s embedded JPG when it is full size.
Other ways to convert DNG to JPG: iPhone, Mac, Windows, Android, Lightroom
- iPhone ProRAW to JPG: Apple says an edited ProRAW photo is shared as a .jpg, and the Mail app “automatically converts the ProRAW file to a smaller JPG file”. This page can also run in a mobile browser — choose the DNG from Files — but we have not yet tested it on an iPhone.
- DNG to JPG on Mac with Preview: open the file, choose File → Export, pick JPEG in the Format menu, set the quality and save; for several, open them in one window and select them in the sidebar. In Photos, choose File → Export → Export [number] Photos and pick JPEG as the Photo Kind. Apple gives DNG files from cameras not on its list “basic support”.
- DNG to JPG on Windows: Microsoft says its built-in DNG decoder “does not support decoding raw sensor data” and shows only the preview stored in the file — small for some phones and drones. The free Raw Image Extension is a viewing codec built on LibRaw. For converting at full resolution, use this page or an editor.
- Android: Pixel phones save RAW and JPEG together, and Samsung’s Expert RAW saves both too — check your gallery for the JPG before converting.
- Lightroom Classic and Photoshop open DNG and export JPEG. Adobe DNG Converter does the opposite job: it converts other RAW files to DNG, not to JPG.
Converting Canon or Sony RAW files instead? The CR3 to JPG and ARW to JPG converters use the same decoder.
Can you convert JPG to DNG?
Not usefully. A JPG holds 8-bit developed pixels; putting them in a DNG container cannot bring back the sensor data that was never in it. Adobe DNG Converter converts camera RAW files, not JPGs. Keep the original DNGs if you may want to edit them later.
Why nothing is uploaded
Many online converters send your photos to their servers and keep them for a while. Here, the RAW decoder (LibRaw compiled to WebAssembly) is downloaded once from this site and runs in your browser tab; it is only allowed to connect to this site, to load its own files. While we converted 12 DNG files, no request carried any part of a photo; the only other requests went to Google Analytics, for the page-view statistics described in the privacy policy. You can check: open your browser’s developer tools on the Network tab while converting.