YouTube Chapter Marker Generator

YouTube's chapter system lets viewers jump to specific sections of a video directly from the progress bar and the description. It is useful for tutorials, conference talks, podcast replays, and product demos where different viewers want different sections. To activate chapters, four specific rules must all be satisfied simultaneously: the first timestamp must be at exactly 00:00; there must be at least three chapters; each chapter must be at least 10 seconds long; and each timestamp must appear at the very beginning of its line in the description, with no characters before it. Miss any one of these rules and YouTube silently ignores the entire chapter list — no error, no partial chapters, nothing.

The AT USE YouTube Chapter Marker Generator validates your timestamp list against all four rules, flags every violation with the specific line and rule it breaks, and outputs a clean description block formatted correctly for YouTube's parser. It runs entirely in the browser; your chapter list is not transmitted anywhere.

What YouTube's parser reads

YouTube scans the video description line by line, looking for lines that begin with a timestamp in MM:SS or H:MM:SS format followed by a space and a label. The parser stops treating a line as a chapter entry if any non-whitespace character precedes the timestamp — including bullets, dashes, numbers, or leading spaces. This is why copying a chapter list from a Google Doc or spreadsheet sometimes breaks chapters: formatting characters that look invisible in a word processor appear as leading characters in YouTube's parser. The generator outputs plain text with nothing before each timestamp.

Common rule violations

The most common reason chapters fail to appear: the list begins at 0:01 or 0:05 instead of exactly 0:00. YouTube requires the first chapter to cover the start of the video. Second most common: a chapter pair with timestamps only 5 or 8 seconds apart, which falls below the 10-second minimum. Third: a list of only 2 chapters, which does not meet the 3-chapter minimum. The generator detects and flags all of these, and offers one-click fixes for the cases that can be corrected automatically (out-of-order timestamps, missing 00:00 start).