SynthID vs C2PA: What's the Difference?

SynthID and C2PA both exist to mark an image as AI-generated, but they work in opposite ways: C2PA is removable metadata stored in the file's header, while SynthID is a durable watermark woven into the pixels. That single distinction — header versus pixels — explains almost everything about how each one behaves, including why one strips off easily and the other doesn't.

Here's the clean comparison.

C2PA in one line

C2PA Content Credentials are a provenance record attached to a file: who or what made it, and how. The data sits alongside the pixels in the file header (in JPEGs, a dedicated metadata segment). Because it's header data, any C2PA-aware tool can read it — and re-encoding the file drops it.

SynthID in one line

SynthID is Google's invisible watermark, embedded *in* the pixels as a faint pattern a matching detector can spot. It's built to survive cropping, resizing, screenshots, and recompression, which makes it far more persistent than any header tag.

The core difference

Three contrasts capture it:

• Where it lives. C2PA: the file header. SynthID: the pixels.
• Who can read it. C2PA: anyone with a standard metadata reader. SynthID: only a matching detector (and there's no general public one).
• How removable it is. C2PA: cleanly, with a re-encode. SynthID: not reliably — it's designed to persist.

In short, C2PA is documentation you can shred; SynthID is a stain in the fabric.

Which one is on your photo?

It depends on the tool that made the image, and a photo can carry one, both, or neither:

• C2PA is added by many AI image tools and some cameras and editors. You can check for it with a free metadata checker — if it's there, you'll see it.
• SynthID comes from Google's models and a growing set of adopters. You generally can't verify it directly; your best clue is knowing the source. See how to check if an image has SynthID.

If you only ever check for C2PA and call it clean, you might still be missing a pixel watermark. Knowing both exist keeps you honest about what "clean" means.

What it means for dating photos

For a profile, the practical upshot is:

• C2PA is worth removing so your file isn't broadcasting a provenance manifest — and it's easy to remove.
• SynthID can't be counted on to remove, so the only real control is whether it was ever added.

The way to sidestep both is to start with a clean file. Our AI dating photos are generated on open models that don't embed SynthID and re-encoded so no C2PA ships either — neither tag to deal with. For the watermark side in depth, see our SynthID guide.

Frequently Asked Questions

Is SynthID the same as C2PA? No. C2PA is removable metadata in the file header; SynthID is a durable watermark inside the pixels. They're separate systems that happen to share a goal.

Can a photo have both SynthID and C2PA? Yes. Some Google-generated images carry both — a C2PA manifest you can read and remove, plus a SynthID watermark you can't reliably remove. It can also have neither.

Which is harder to remove, SynthID or C2PA? SynthID, by a wide margin. C2PA strips off with a clean re-encode; SynthID is engineered to survive edits.

How do I check for each? Use a [metadata checker](/c2pa-checker) for C2PA, EXIF, and XMP. For SynthID there's no general public detector — your best signal is what tool produced the image.