C2PA Metadata Explained

C2PA metadata is a signed, tamper-evident record of a file's origin and edit history, embedded inside the file itself. Defined by the Coalition for Content Provenance and Authenticity, it binds a cryptographic signature to the content so any later alteration breaks verification.

What C2PA metadata actually contains

A C2PA manifest records assertions about a piece of content: who or what produced it, when, with which device or software, and what actions were applied afterwards. Each manifest is signed, so a verifier can check both the claims and the fact that the bytes have not changed since signing. Crucially, C2PA does not assert that content is true, safe or human-made. It asserts that a specific signer stood behind a specific set of statements about a specific file.

In-band vs out-of-band provenance

In-band means the manifest lives inside the file — a JUMBF box in JPEG (APP11), a chunk in PNG, or an appended block in PDF. Out-of-band means the manifest is stored separately and located by the file's hash. In-band survives copying and re-hosting. Out-of-band survives metadata stripping. Serious deployments use both: the manifest is embedded, and the same evidence is discoverable by hash if the embedding is lost.

Why C2PA metadata disappears

Most social platforms, messaging apps and CMS pipelines re-encode uploads. Re-encoding rewrites the container and drops anything the encoder does not understand — including Content Credentials. A screenshot destroys them outright. This is the single biggest operational gap in C2PA-only strategies: the evidence is correct, and then it is simply not there any more.

Making provenance survive the internet

The durable pattern is layered. Embed the manifest for tooling that reads it. Register the content hash in a public, append-only transparency log so the same evidence can be retrieved even from a stripped copy. Add a perceptual signal so a re-encoded or cropped derivative can still be linked back to a registered original. Each layer degrades independently. A verifier reports what it found, and what it could not confirm — rather than a binary verdict.

How AxIA works with C2PA

AxIA treats C2PA as one evidence source among several, not as the product. Signed content is published with an embedded manifest where the format allows it, and every signature is recorded in a public transparency log with an inclusion proof. The result: standard C2PA readers see standard Content Credentials, and anyone else can verify the same file by hash even after the metadata is gone.

How to check a file for C2PA metadata

• 1 Keep the original file Download the original asset rather than a screenshot or a re-shared copy — re-encoding removes embedded metadata.

Keep the original file

Download the original asset rather than a screenshot or a re-shared copy — re-encoding removes embedded metadata.

• 2 Open it in a Content Credentials reader Any C2PA-compatible viewer will list the manifest, the signer and the recorded assertions if they are still present.

Open it in a Content Credentials reader

Any C2PA-compatible viewer will list the manifest, the signer and the recorded assertions if they are still present.

• 3 Verify by hash if metadata is missing Compute the file's SHA-256 and query a transparency log. Registered content resolves even when embedded metadata has been stripped.

Verify by hash if metadata is missing

Compute the file's SHA-256 and query a transparency log. Registered content resolves even when embedded metadata has been stripped.

• 4 Read the result carefully A valid signature proves integrity and signer identity. It does not prove the content is accurate, or that no AI was involved unless that was explicitly declared.

Read the result carefully

A valid signature proves integrity and signer identity. It does not prove the content is accurate, or that no AI was involved unless that was explicitly declared.

Frequently asked questions

What does C2PA stand for?

The Coalition for Content Provenance and Authenticity, an open standards body whose specification defines Content Credentials — signed provenance metadata embedded in media files.

Does C2PA prove that content is real?

No. C2PA proves that a signer made specific statements about a file and that the file has not changed since. It cannot prove factual accuracy, editorial intent or human authorship.

Why does C2PA metadata get removed by social media?

Platforms re-encode uploaded media to optimise delivery. Re-encoding rewrites the file container and discards metadata blocks the encoder does not preserve, including Content Credentials.

Which formats support embedded C2PA today?

In production, image formats such as JPEG (via JUMBF in APP11) and PNG are the most widely supported, with PDF and video support varying by tool. Support outside images remains uneven across the ecosystem.

Can provenance survive when metadata is stripped?

Yes, if the content hash was registered in a public transparency log at signing time. The file can then be verified by recomputing its hash, with no dependence on embedded metadata.

Verify a file now

Check any file against the public transparency log — no account required.