Is EXIF the only hidden data in a photo?

By Check Before Send · Updated 13 October 2026

No. EXIF is the best known block, but a JPEG photo can also carry XMP, IPTC and plain comment blocks, and software can add segments of its own. A tool that clears only EXIF can leave a name, a caption or a note in the file.

This guide explains what each block is, why a photo file has room for them, and what we found in test photos that carried one block each.

Why a photo file has room for more

The JPEG standard sets aside application data segments and a separate comment segment. It says the comment bytes are interpreted by the application, and that application segments are reserved for application use and may be defined differently by different applications. In other words, the format does not decide what goes in them. The program that writes the photo does.

That is how several systems ended up in one file:

EXIF is the camera's table of tags: time, device, settings and sometimes GPS.
XMP is, in Adobe's words, a technology for embedding metadata in files themselves. It is also an ISO standard, according to Adobe's page.
IPTC is the photo metadata standard used by news agencies, photographers and photo libraries. It covers names, dates, rights information and descriptions. IPTC says its newer schemas use XMP, and that an older format called IPTC-IIM came first.
A comment is free text that any program can leave.

What we tested

We made small test photos with invented values, each carrying one kind of block, and ran Check Before Send on each.

Test photo	What the tool listed	After removal and a second scan
XMP block only	Creator name	Nothing found
IPTC block only	Caption and byline	Nothing found
Comment segment only	The comment text	Nothing found
Extended XMP block	An extended XMP block	Nothing found
A segment the tool does not recognise	An unrecognised metadata segment	Still listed, and the result is marked as not fully checked

The first four are the reason for this guide: a tool that handled only EXIF would not have touched any of them. The last row is the honest limit. When a segment is unrecognised, the tool says so, and it does not call the file clean, because it cannot say what the segment holds.

In each of the first four, the decoded pixels of the original and the copy were identical.

Limits

These are tiny synthetic photos, with one block each. A real photo often has several at once. We did not scan every program's output, and a segment we cannot read is a gap, not a pass.

What to do

Ask what program last saved the photo. Editors and photo managers often write XMP and IPTC.
Do not trust a tool that says "EXIF removed" as the whole answer.
Check the copy you are about to send, and read the list for anything marked as not recognised.

Check the photo before you send it

Drop the photo into Check Before Send. It lists each block it finds and what is in it, you choose what to remove, and it writes a new copy and runs a second scan on that copy. "Verified not found" means that second scan found nothing, not that the file is guaranteed clean.

The photo is read inside your browser and is not uploaded; the Trust Center explains how to confirm that. For the EXIF part on its own, see what EXIF data is, or browse the other guides.

Sources

More guides

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