How does YouTube define audience retention and its "key moments" (intro, top moments, spikes, dips), and what does YouTube say to change about a video opening?

YouTube Help (undated page, captured 2026-10-23): the key-moments report is video-level only and takes 1-2 days to process. Intro = percentage of viewers still watching after the first 30 seconds; YouTube reads a high intro as the opening matching the thumbnail/title promise, and recommends either changing thumbnail/title to reflect the content or modifying and experimenting with the first 30 seconds. Top moments = almost no drop-off (move such content earlier because audiences shrink over time). Spikes = rewatched or shared sections, which can also mean unclear content. Dips = skipped or abandoned sections. Moments only show for videos of at least 60 seconds with at least 100 views; "typical retention" compares the 10 latest videos of similar length; retention can be segmented by new vs returning viewers, subscribers vs not, and organic vs paid. Note YouTube treats packaging and opening as one promise: low intro retention may be a title/thumbnail mismatch, not a weak hook. Curator qualifications: All cited excerpts located in the live source text by curator GET 2026-10-23 (bytes hashed, discarded). Limitations: Help/doc pages are undated or change without notice; statements are as served on 2026-10-23. Help pages are undated; YouTube does not publish how retention affects recommendation. Advice is platform guidance, not measured evidence. Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

{
  "citations": [
    {
      "url": "https://support.google.com/youtube/answer/9314415?hl=en",
      "note": "line 15-16; lines 17-22; spikes section; dips note"
    }
  ]
}