Chapter Marker Builder

// Validate and format YouTube chapter timestamps

YouTube renders video chapters when the description contains properly formatted timestamps that meet specific rules. This tool validates your chapters against those rules and outputs a YouTube-formatted block ready to paste into your description.

Chapter input

Paste a chapter block in any common format. The tool parses timestamps and titles separated by whitespace or punctuation.

Validation

Formatted output

Paste this into your video description. The first chapter must be at 0:00 for YouTube to render the chapter UI.

YouTube chapter rules

First chapter: Must start at 00:00
Minimum count: At least 3 chapters
Minimum gap: Each chapter at least 10 seconds long
Order: Timestamps must be in ascending order
Format: One chapter per line: TIMESTAMP TITLE (e.g. 0:00 Intro)
Timestamp format: MM:SS or H:MM:SS or HH:MM:SS