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DNG is the one RAW format that comes from everywhere: converted from other makers’ files, written directly by some cameras, drones and phones. A DNG from a phone usually carries the exact position where it was shot, the phone model and software version, and a full-size JPEG preview that repeats all of it. A DNG metadata remover deletes those fields, cleans the preview as well, and leaves the raw sensor data and the instructions a RAW editor needs to develop it exactly as they were. Add a DNG above, read what it held and download a clean copy. DNG files are processed on our server and deleted within minutes.
Where DNG files come from
- Phones. Apple’s ProRAW format, introduced with the iPhone 12 Pro, is a DNG. Android phones from several makers can save DNG too.
- Drones and some cameras. Several drones and a number of cameras write DNG directly instead of a maker-specific RAW format.
- Adobe DNG Converter and Lightroom. Both can convert a maker’s RAW file into a DNG, and the result can carry the original file name, and even the original file itself.
What a DNG carries
| Where | Tags | What they reveal |
|---|---|---|
| First directory and EXIF | Make, Model, Software, DateTimeOriginal, CreateDate, ModifyDate | The device, its software version and when the picture was taken |
| GPS | Latitude, longitude, altitude, speed, direction, date stamp, positioning error | Where the picture was taken, and how accurately the position was known |
| DNG identity tags | CameraSerialNumber, OriginalRawFileName, OriginalRawFileData | A camera’s serial number, the name of the file this was converted from, and sometimes that whole file |
| XMP | Edit settings from Lightroom or Camera Raw; descriptors of extra images | How the file was edited and what it contains |
| Previews and extra images | A JPEG preview in the first directory, and other images such as mattes or depth data | Pictures that can carry their own copy of the metadata |
| Maker notes | Phone-specific data, for example Apple’s group of 24 tags in the file we tested | Device-specific details |
| Raw data and rendering tags | Raw tiles or strips, colour matrices, black levels, crop, opcodes | What a converter needs to develop the picture. Not personal |
What we found in a real iPhone ProRAW file
The sample is a public CC0 file from raw.pixls.us: a 29.2 MB ProRAW DNG from an iPhone 12 Pro, run through the production cleaner and checked independently with ExifTool.
- GPS: 14 tags, covering latitude, longitude, altitude, speed, the direction the phone faced, a destination bearing, the date stamp and a positioning error of about five metres.
- Software: 14.3, the iOS version, which is the release that introduced ProRAW.
- Dates: the capture, creation and modification times.
- XMP: three small groups, one of which describes an auxiliary image as a sky matte.
- A 5.3 MB JPEG preview that held its own copy of the metadata, including the same 14 GPS tags, the phone model and the host computer name.
After cleaning, the report showed 21 fields removed and none left. The file was 175 KB smaller. We then checked the result independently:
- All 64 raw image tiles were identical byte for byte before and after.
- The preview’s pixels were identical, and the metadata inside it was gone.
- The smaller extra image in the file was left as it was.
- Apple’s 24 maker-note tags and the DNG rendering tags (colour matrices, calibration illuminants, black level, crop size, baseline exposure) read exactly the same.
- ExifTool’s validation reported one minor warning after cleaning, against two before: the original’s warning about non-standard XMP went away with the XMP.
Previews carry their own metadata
A RAW file’s embedded JPEG is a complete image, and a program that builds it can copy the camera’s metadata into it. That is what happened here: the phone’s 5.3 MB preview held GPS, device and date information, so cleaning only the DNG’s own tags would have left the position in the file. ExifTool does not look inside those pictures when it edits a RAW file, so the tool extracts each preview and thumbnail, checks it separately, and rewrites any that carries personal tags without them. If a format would not accept the rewrite, the preview is removed instead, and the report lists it as an embedded preview if anything is left.
Not every camera does this. The previews in the Canon, Nikon and Sony files we tested carried no personal tags and were left untouched. Phones and some converters are where it mattered.
XMP: edit settings and descriptors
A DNG saved from Lightroom or Camera Raw can hold your develop settings in its XMP, and those go when the XMP goes: the cleaned file opens as an unedited RAW. In the ProRAW file the XMP held no edits. It described an auxiliary image, a sky matte, which Apple’s own software may use for photo effects. The matte itself, and the raw data, are still in the file, but we have not tested whether Apple’s software still offers those effects once the descriptor is gone. If you hand a file to an editor, this will not matter. If you keep it for use in Apple’s tools, keep the original.
DNGs that embed the original RAW file
Adobe DNG Converter has an option to embed the original RAW file inside the DNG. A DNG made that way contains a complete copy of the camera’s file, with all of its metadata, whatever has been removed from the DNG’s own tags. The tool deletes the name of the original file and the embedded original wherever ExifTool allows it, and the report names either one if it stays. We had no DNG with an embedded original to try this on, so treat this part as untested, and re-export without the embed option if you can.
What stays
- The raw data and the extra images, unchanged.
- The tags that control development: colour matrices, calibration illuminants, black and white levels, crop and the as-shot neutral.
- Camera make and model, and the unique camera model string a DNG requires.
- The maker notes of the phone or camera, apart from the fields listed above.
Clean a DNG in four steps
- No account needed to start. Guests can clean 5 RAW photos a month, a free account 10.
- Add the DNG. Drag it anywhere on the page. The upload shows its progress.
- Wait for the clean. The server removes the fields, cleans the previews and scans the result.
- Read the report. It lists what was found, with the preview named if it carried metadata, and how many fields remain.
The size limit is 25 MB for guests, 25 MB on a free account, 100 MB on Starter, 500 MB on Pro and 1,000 MB on Business. The ProRAW file above, at 29 MB, does not fit a free account, and phone DNGs commonly run from 25 MB to over 100 MB. The original is deleted as soon as cleaning finishes, and the clean copy is kept for at most 15 minutes. See pricing.
exiftool -a -G1 -s -gps:all -alldates -software -xmp:all clean.dng
exiftool -b -PreviewImage clean.dng | exiftool -a -G1 -s -gps:all -The RAW photo metadata remover page covers every format, and the CR2, NEF and ARW pages describe what we found in Canon, Nikon and Sony files.
Frequently asked questions
Does cleaning change the DNG’s raw data?
No. We compared all 64 raw image tiles of a real ProRAW file before and after cleaning and they were identical byte for byte. The colour matrices and other development tags read the same too.
Does it remove GPS from iPhone ProRAW files?
Yes. All 14 GPS tags in the test file were removed from the DNG itself, and from the embedded preview, which carried its own copy.
Why does the preview matter?
A preview is a full JPEG that can carry its own EXIF, including GPS. In the ProRAW file it did. A cleaner that only edits the DNG’s tags would leave the position in the preview.
Will it remove my Lightroom edits?
Edit settings stored in the file’s XMP are removed along with the XMP, so the cleaned DNG opens as an unedited RAW. Edits kept in a sidecar file or a catalog are not touched.
Does it remove an embedded original RAW file?
It tries to, wherever ExifTool allows it, and the report names it if it stays. We did not have a sample to test it on.
Will my RAW editor still open the file?
The file validates in ExifTool and the raw data and development tags are unchanged. We could not try every editor, so open a clean copy in yours before handing files over, and keep the originals.
Is my DNG uploaded?
Yes. RAW needs ExifTool, so the file is uploaded over HTTPS to our server. The original is deleted when cleaning finishes and the clean copy within 15 minutes. We never open the picture.
Does it work on DNG files from drones and other cameras?
It cleans any DNG the same way. We tested a phone file, so a drone or camera DNG is covered by the method but not by a test of its own.
Is the depth or portrait data in my ProRAW file kept?
The extra image is kept. The XMP that describes it is removed, so Apple’s own tools may no longer recognise it as a matte. We have not tested that, and a RAW editor does not need it.