YouTube's chapter rules are a parser, not guidance. Break one of the four and you get no chapters at all — not the valid ones, none of them — with no error anywhere on the page.
YouTube chapters not showing is almost always one of four things: the first timestamp is not exactly 00:00, there are fewer than three, one of them runs under ten seconds, or they are not in ascending order. Break any one and YouTube draws none of them — not just the offending line, all of them — and it tells you nothing.
That last part is why this question gets asked so often. There is no warning in YouTube Studio, no red text under the description, no note on the video page. The chapters are either there or they are not, and the description looks identical either way.
The four rules, in the order they get broken
YouTube's own chapters help page states them plainly. They are not style guidance. They are a parser, and it either matches or it does not.
Rule
What it means
How it usually breaks
First timestamp is 00:00
Exactly zero, on its own line
Someone starts at 00:01, or puts a "Chapters:" heading in the way
At least three chapters
Three lines, minimum
A two-chapter video, or a third line that failed to parse
Each runs ten seconds or more
Measured to the next timestamp
Two chapters typed a few seconds apart while watching
Ascending order
Each later than the last
A chapter added afterwards and appended to the bottom
Notice the second column of the third row. A chapter's length is not a property of the chapter; it is the gap to the one after it. So a chapter you thought was two minutes long is eight seconds long if you typed another timestamp eight seconds later, and that eight-second gap removes every chapter in the video.
Cause one: the first timestamp is not 00:00
This is the most common single cause, and the most annoying, because the mistake is invisible when you read the block back.
0:00 and 00:00 both work. 00:01 does not. A line above the first timestamp does not stop it working, but a line that looks like a timestamp and is not — 0.00, 0;00, 00 00 — does, because it does not parse, so the first thing that does parse is your second chapter.
There is a temptation to solve this by adding an "Intro" chapter over the ninety seconds before your first note. Sometimes that is right. Often it is not, because the first ninety seconds are the thing you were about to describe and you have now labelled them something generic.
The formatter reads whatever shape you typed — before or after the label, in brackets, with dashes — and rebuilds the block. It will not invent a 00:00 line, on purpose: it says the first chapter is missing and leaves the decision to you.
Cause two: fewer than three chapters
Three is the floor. A video with two meaningful sections does not get a chapter list, and there is no partial credit.
The usual version of this is not a two-chapter video. It is a five-chapter video where three lines parsed and two did not, leaving two valid ones. Look for a line where the time uses a full stop instead of a colon, or where an emoji sits immediately against the number.
Cause three: a chapter under ten seconds
The ten-second minimum applies to every chapter including the last, whose length runs to the end of the video.
This one is easy to introduce by accident and hard to spot by eye, because two timestamps eight seconds apart look perfectly reasonable in a list:
text
0:00 - Intro
0:12 - What we are making
0:19 - Ingredients
2:40 - Method
0:12 to 0:19 is seven seconds. Nothing in that description will draw a single chapter, and three of the four lines are innocent.
Cause four: they are out of order
A description is parsed top to bottom. A chapter that goes backwards ends the list — everything after it is ignored — which most often happens when you remember a section afterwards and append it rather than inserting it.
Sorting is safe and there is no reason not to do it. The order in the description has to match the order in the video, and nothing else about the block cares.
What is not a cause
Several things get blamed for this and none of them are it:
A "Chapters:" heading. Harmless. The parser looks for the pattern, not for a label.
Where the block sits in the description. It does not have to be at the top.
Dashes, em dashes, pipes or nothing between the timestamp and the label. All fine.
Video length. There is no minimum duration for chapters to appear.
Monetisation status, age or view count. Irrelevant.
One thing that is real and gets missed: chapters can be disabled at the channel level in YouTube Studio, under Settings → Upload defaults → Advanced settings, and under Video details → Show more for a single video. If a perfectly valid block still draws nothing, check there before rewriting it again.
When YouTube chapters are still not showing after all four
If every rule checks out, the next thing to rule out is a timestamp in the wrong place. A timestamp typed into a comment becomes a clickable seek automatically, which is genuinely useful and is not the same feature. Comment timestamps never create the segments on the progress bar; only the description does.
That distinction matters when you are using the first comment to carry links and jump points. What to put in a pinned comment covers what that block is for, and YouTube timestamp links covers building a link to a moment in someone else's video.
Getting the block right once
Chapters are worth the ten minutes because they change what the video looks like in search — the segments appear under the result — and because they let somebody skip to the part they came for instead of leaving.
The description they live in is doing several jobs at once, and the chapter block is only one of them. The YouTube description template covers the rest of the blocks and the order they go in.
Why are my YouTube chapters not showing?
Almost always one of four rules: the first timestamp is not exactly 00:00, there are fewer than three chapters, one runs shorter than ten seconds, or they are out of order. Any one of them removes every chapter, with no error displayed.
Does the first YouTube chapter have to start at 00:00?
Yes, exactly. 00:01 does not work, and neither does a line that only looks like a timestamp.
How short can a YouTube chapter be?
Ten seconds, measured to the next timestamp. One short chapter invalidates the whole list rather than only itself.
How many chapters does a YouTube video need?
Three at minimum. There is no maximum, though a chapter list longer than about a dozen stops being useful to scan.
Do timestamps in a comment create chapters?
No. They become clickable seeks, which is useful, but only the description creates chapters on the progress bar.
Paste your notes into the chapter title formatter and it will tell you which of the four rules you are still breaking.
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