There is no reliable one-click test that tells you whether a video is AI-generated. The strongest evidence is provenance: a signed Content Credentials (C2PA) manifest or a maker’s watermark that says an AI tool made the clip; after that come the file’s other metadata, what you can see and hear, and above all where the video came from.
Each of those checks can confirm an AI origin when it finds something, and none of them can prove a clip is real when it finds nothing. Most videos you meet online have been re-uploaded, and platforms strip metadata as a matter of routine, so a genuine phone clip and an AI clip downloaded from social media often look identical at the file level.
This site can help with the metadata part. Open a video here and the Provenance section shows any Content Credentials, the AI-generation assertion if there is one, encoder and software tags, and signs of re-saving. It reads the file in your browser and uploads nothing. It does not judge pixels, does not verify signatures and cannot read invisible watermarks; this guide says where to go for those.