YouTube Chapters Checker
Paste your description or timestamp list. You'll see which of YouTube's chapter rules it breaks, how long each chapter is, and a cleaned-up list ready to paste back in.
Check chapters in three steps
Paste the description
The whole thing is fine: lines without a timestamp are ignored.
Add the video length
Optional, but it lets the last chapter be checked too.
Fix and copy
Fix anything flagged, then copy the clean list into YouTube Studio.
YouTube's chapter rules
YouTube turns timestamps in a description into chapters on the progress bar only if all of these are true: the first timestamp is 0:00, there are at least three timestamps, they're in order, and every chapter is at least 10 seconds long.
Each timestamp needs to be at the start or end of its own line with the chapter's title, like "1:15 Setup". Brackets, dashes and bars are fine; this checker accepts them and writes the clean version without them.
If the list passes and chapters still don't show, give it a few minutes after saving the description, then reload the video page.
Common timestamp mistakes
Starting at 0:01 or with the intro skipped
The first line must be 0:00, even if it's just "0:00 Intro".
A quick 5-second chapter
Merge it into the chapter before or after: every chapter needs 10 seconds.
Only two chapters
Add a third: YouTube needs at least three.
Timestamps out of order after editing the video
Re-check every time after a re-cut; the checker flags any that go backwards.
Frequently
Asked Questions
Why aren't my YouTube chapters showing?
Usually the first timestamp isn't 0:00, there are fewer than three, or one chapter is under 10 seconds. Paste the list above to see which.
Do timestamps need to be in 00:00 format?
No. 0:00, 00:00 and 0:00:00 all work; for videos over an hour use h:mm:ss.
How long does a chapter need to be?
At least 10 seconds.
Is my description saved?
No. It's checked in your browser.