Tagg the Builder guides you through Markup City. Standing in the way: The Unclosed Tag — every mistake this lane teaches you to avoid. Your origin story. Elements, attributes, headings, links — the bricks every page on earth is built from.
All 39 lessons below are free, need no signup, and each one opens as a comic issue with a live try-it sandbox, a task list that pays XP, and a narrator that reads it aloud. Progress is stored in your own browser — nothing is uploaded anywhere.