Who can check a mark after the file is delivered
Five entries name somebody who can verify their mark. Two name routes anybody can take, two name routes scoped to the vendor's own output, and one names a coalition rather than a tool. As of 2026-09-12.
| Point | Where it sits | What the record holds |
|---|---|---|
| A public destination | Two entries | A verification site, and publicly available tools |
| Scoped to the vendor's own files | Two entries | A detector that finds only marks that vendor wrote |
| An ecosystem rather than a tool | One entry | A coalition figure, with no software enumerated |
Inclusion rule. Entries describing a mark that something has to read. Entries describing only a visible notice are excluded, because the reader of those is a person. Order. Widest reach first, narrowest last.
1Interoperability is the word this column is really about
The marking paragraph asks for solutions that are effective, interoperable, robust and reliable as far as technically feasible. Three of those a single team can build and measure alone; the fourth needs somebody else.
Where the reach comes from a published specification, it arrives whether or not the vendor helps. Where it comes from the vendor's own tooling, it stops at whoever has a relationship with that vendor.
2A narrow route stated plainly beats a broad one implied
One entry says its detector finds only the marks its own systems wrote and will not find another platform's. That sentence narrows a claim the vendor could have left open, and it is more useful to a reader than the open version.
Another describes its tools as internal, which is the same honesty about a different boundary. Both let a reader plan around a limit instead of discovering it when a check returns nothing.
3What a negative result is worth
From a single-vendor detector, nothing found means that vendor's mark is absent. From a public manifest reader, nothing found means no manifest arrived, which a stripping route produces as reliably as an unmarked file.
In neither case does absence establish that content is authentic. A reader who treats it that way has been misled by the tool rather than by the page, and both pages here are careful about saying so.
- Amazon Nova ReelCredentials can be inspected by dropping a generated video into publicly available verification toolswho can read the mark
- Microsoft DesignerProvenance metadata can be viewed on the Content Credentials sitethe route a viewer uses to read it
- OpenAI SoraInternal detection tools to help assess whether a video or audio was created by the vendor's productsthird item on the same list
- ElevenLabsThe detector can only find watermarks embedded by this vendor and will not find those of other platformsthe reach of the checking route
4Sources
Article wording from AI Act Explorer, Article 50; vendor statements from the pages listed on each generator entry. Both read 2026-09-12. Related: The audio half, Open weights, What an omission proves.