Start from the captions
Paste a public link on /youtube-summary. If YouTube published a caption track, the recap uses those lines. No captions means no summary. We do not listen to the audio and invent a recap.
Chapters when the creator set them
A long lecture splits on the chapters YouTube already has. A video with no chapters gets one recap for the whole caption file. You can open the lines underneath and check a sentence.
The on-page recap is extractive
It quotes the opening sentences of each span. It does not call GPT on our servers, and it does not bill you for a model. Names and jargon are only as good as the captions.
When you want your own model
The Summary button copies a prompt with the transcript attached. Paste that into the chat you already pay for. The Notes and Quotes prompts are the same idea with a different shape.
What a summary is not
It is not a new video, and it is not a subtitle file. Audio and the video file are separate pages. The recap stays on the result URL for that video, and that result URL stays out of Google’s index.