Real seams
Chapter breaks land where the topic shifts, on your transcript’s own timestamps.
Viewers leave long videos when they cannot find the part they came for. Chapters fix that: they turn a timeline into a table of contents, let search engines deep-link into specific moments, and give returning viewers a way back to the section they need.
Good chapters follow two rules. Breaks must match real topic changes, and titles must describe the content. "Setting the audience filter" gives viewers and search engines useful detail. "Step 3" does not.
YouTube adds format rules of its own: the list must start at 0:00, carry at least 3 chapters, and give each chapter at least 10 seconds. The YouTube output here checks all three and tells you when a list breaks one.
If you already have chapter titles and timestamps and only need them re-formatted, the deterministic video chapter formatter does that instantly, with no AI involved.