Paste chapter lines with timestamps, check them against the chapter rules, and copy a clean block ready for a video description.
Timestamps can be MM:SS or HH:MM:SS. The output normalises every timestamp to a consistent form and keeps the titles as written.
Video chapters are just lines in the description, each holding a timestamp and a title, but they only turn into clickable chapters when a few rules are met: the first chapter must start at 00:00, there must be at least three chapters, and each chapter must be at least ten seconds long. This tool reads lines in MM:SS or HH:MM:SS form, sorts them into time order, checks each rule and reports pass or fail per rule so a failed chapter list can be fixed instead of guessed at. The output block uses one consistent timestamp style throughout and can be pasted straight into a description. Chapter titles are kept exactly as written.
What are the rules for chapters to appear on a video? The description needs at least three chapter lines, the first one must start at 00:00, and every chapter must be at least ten seconds after the previous one. This tool checks all three and shows which rule failed when one does.
Can timestamps use hours? Yes. Both MM:SS and HH:MM:SS are accepted, and they can be mixed. If any chapter is an hour or longer, the output writes every timestamp in HH:MM:SS form for consistency.
Does this upload the video or edit its description? No. This tool only formats text in the browser. The resulting block is copied and pasted into the description manually.