Forty-two is the whole trick
A TIFF opens with two bytes saying which end its numbers start from — II for Intel, MM for Motorola — and then writes the number 42 in that order, as a check that you read the first two bytes correctly. Canon CR2, Nikon NEF and NRW, Sony ARW and SR2, Pentax PEF, Samsung SRW and Adobe DNG all do exactly that, because they are TIFF files with extra image file directories bolted on. A reader that walks TIFF walks them, without knowing anything about cameras.
Which ones this reads, and which it turns away
Olympus and Panasonic write their own number where TIFF writes 42 — ORF puts RO or SR there, RW2 puts 85 — so a TIFF reader stops at the fourth byte. Fujifilm RAF does not begin with a byte-order mark at all; it begins with the text FUJIFILMCCD-RAW. And CR3, despite the name, is not a descendant of CR2: Canon moved it to the ISO base media container, the same one HEIC uses. Those four are turned away at the drop zone rather than accepted and failed on afterwards.
The maker note is why you opened it
The standard EXIF tags in a raw file say roughly what a JPEG would: camera, lens, exposure, time, sometimes coordinates. What a raw file has that its JPEG sibling usually does not is a full maker note — a proprietary directory in the manufacturer own layout, holding the shutter count, which focus points were active, the picture style, lens serial numbers and firmware. It is shown here tag by tag, as found, rather than tidied into a guess.
There is a JPEG inside, and this does not open it
Every raw file carries at least one embedded JPEG preview, which is what the camera screen and your file browser show you. That preview usually holds its own copy of the EXIF. It is worth knowing about, because a workflow that cleans the raw and forgets the preview has not done what it thinks it has. This reads the raw file own directories; it does not extract the preview or what the preview carries.
Reading is all there is
No browser decodes a raw file, and every cleanup path here for a format other than JPEG works by decoding the image and drawing it again. With nothing to draw there is nothing to write back, so a raw file is offered no cleanup rather than a button that would fail. Taking anything out of one needs a tool that understands the format.
What is behind each extension
- CR2 · NEF · NRW
- TIFF, magic 42. Canon and Nikon. Read here.
- ARW · SR2 · SRF
- TIFF, magic 42. Sony. Read here.
- DNG
- TIFF by specification — a documented TIFF profile rather than a format of its own. Read here.
- PEF · SRW
- TIFF, magic 42. Pentax and Samsung. Read here.
- ORF · RW2
- TIFF-shaped, but Olympus and Panasonic write their own number where TIFF writes 42. Turned away.
- RAF
- The Fujifilm container, beginning with the text FUJIFILMCCD-RAW. Turned away.
- CR3
- The ISO base media container HEIC uses, not a descendant of CR2. Turned away.
Questions about raw files
Why can I read the file but not see it?Open
Reading metadata means walking a directory of tags near the front of the file. Showing the picture means decoding sensor data laid out the way one manufacturer chose, which no browser implements. The first is cheap and general; the second is why raw converters exist.
Is a DNG the same as the file my camera wrote?Open
Usually not. A DNG produced by converting is a new file, and the converter decides what comes across — many keep the original maker note as a block, some do not. If you are checking what your camera recorded, check the file your camera wrote.
Can I take the location out of a raw file here?Open
No. Every removal path for a format other than JPEG decodes the image and redraws it, and no browser decodes raw. The coordinates are shown so you know they are there; removing them needs a tool that understands the format.
Does this read the embedded preview?Open
No. A raw file usually holds one or more JPEG previews carrying their own EXIF, and this reads the raw file directories instead of extracting them. A tag missing from the output was missing from what was read, not filled in from somewhere else.
What it can do
- Remove EXIF data
- Drop a photo and download a copy with its embedded metadata removed. JPEG loses its EXIF segment losslessly; HEIC, PNG, WebP and the rest are re-encoded. Nothing is uploaded.
- Remove GPS location
- See the coordinates a photo is carrying, then download a copy without them. JPEG loses the location tags and keeps everything else. Nothing is uploaded.
- Edit JPEG EXIF
- Change the title, author, description, copyright, software and capture time on a JPEG, then download the edited copy. Runs locally; your original file is never modified.
- XMP, IPTC and ICC viewer
- Read every metadata group a file carries — EXIF, XMP, IPTC, ICC, maker notes — grouped and exportable as JSON. For asset QA, forensics and debugging a pipeline. Nothing is uploaded.
- Open several photos
- Open up to fifty photos, see which of them carry a location, and take the whole set out as a spreadsheet. Nothing is uploaded, and the originals are never written to.