What Adobe documents
Adobe says it automatically applies Content Credentials to assets in which all of the pixels were generated with Adobe Firefly, such as Text to Image results. These credentials are C2PA manifests: signed, tamper-evident metadata attached to the file. According to Adobe they record the issuer, a summary noting that Adobe generative AI was used, the app or device, the AI tool and the general editing actions taken. They are not a visible watermark on the picture.
Source: Adobe Firefly: Content Credentials (opens in a new tab)
Generative Fill and Generative Expand
Firefly also powers editing features inside other Adobe apps. Adobe announced that Photoshop automatically attaches Content Credentials to images in which Generative Fill or Generative Expand was used, when the result is exported as PNG or JPEG or saved with Save As. That means a Firefly credential can describe a photograph with an AI-edited region, not only a fully generated image. Read the recorded actions before deciding which of the two you are looking at.
Source: Adobe Photoshop feature summary (September 2023) (opens in a new tab)
Check the credential in your browser
Choose the file in the checker above. It reads any C2PA manifest with the open-source C2PA SDK inside your browser tab, reports whether the manifest validated against the file, and notes whether it declares AI generation. Nothing is uploaded. The checker does not evaluate whether the signer is trustworthy or show the full edit history; for that, open the original in the Content Authenticity Initiative's Verify tool, which displays the signer, the actions and the ingredients it can read.
Source: Content Authenticity Initiative Verify (opens in a new tab)
Why credentials go missing
A manifest lives in the file, so it disappears when the image is screenshotted, re-encoded by a social platform, exported from software that does not carry it forward, or passed through a metadata cleaner. The image looks the same afterwards. A Firefly image without credentials is therefore common, and the absence tells you nothing about whether Firefly was used. When it matters, ask for the file exactly as it was exported from the Adobe app.
Generated, edited or both
A valid Adobe credential that declares generative AI is good evidence that Firefly was involved in the file's history. It does not show how much of the image changed, whether the caption is accurate, or whether the work is acceptable under a contest, marketplace or newsroom policy. Compare the recorded actions with the creator's own account, look at the edited region in context, and keep the credential findings separate from your conclusion about the claim.
Does Adobe Firefly add a watermark to images?
Firefly attaches Content Credentials, which are signed metadata rather than a visible mark. Some apps and websites show a small Content Credentials icon when they find a manifest, and selecting it reveals the recorded details. Because the credential is part of the file, a screenshot or re-saved copy may not carry it.
Can you tell if Photoshop Generative Fill was used?
If the exported file still carries its Content Credentials, the manifest can record that a generative AI action was applied, and our checker reports a declared AI signal when the manifest says so. If the credentials were stripped, there is no reliable way to prove from the file alone that Generative Fill was or was not used. An unedited original from the camera or phone is the most useful comparison.
Is an image without Content Credentials not from Firefly?
No. Credentials are lost easily, and older exports or other routes may never have carried them. Missing credentials should be recorded as unknown, not as evidence that a person made the image without AI.