What this tool checks
YouTube turns a list of timestamps in your description into clickable chapters on the progress bar, but only if the list follows a few rules. According to YouTube Help (checked October 2026), your chapter list must:
- start with a timestamp of 00:00;
- contain at least three timestamps;
- list the timestamps in ascending order;
- make every chapter at least 10 seconds long.
If any rule is broken, YouTube simply doesn't show chapters, and it doesn't always tell you why. The checker runs each rule and tells you which line to fix. If you enter the video length, it also checks that the final chapter lasts at least 10 seconds before the video ends.
How to use it
- Watch through your edit and note the time each new section starts. Rough notes are fine: "45 setup" or "3:10 - step one" both work.
- Paste the notes into the box, one chapter per line, and press Check and format.
- Fix anything marked "Fix", then copy the formatted list.
- In YouTube Studio, open the video's details and paste the list into the description. Chapters can take a little while to appear after you save.
The tool writes times as 00:00 for videos under an hour and 0:00:00 once any chapter passes the one-hour mark, so every line lines up neatly.
Tips for useful chapter titles
Chapters are navigation, so write them for someone scanning the video for one specific thing. Keep titles short and descriptive ("Fitting the hinge" beats "Part 3"). Avoid repeating the video title, and don't stuff keywords in: viewers see these titles on the progress bar and in search previews. Our longer guide to YouTube chapters and timestamps covers automatic chapters and how to turn them off.
YouTube can also create chapters automatically for some videos. Adding your own list overrides the automatic chapters for that video. Your list never leaves your browser: this page doesn't send what you type to our server.