Tokens & Context Windows

Learn what a token is, how context windows fill up, and why cost and quality both hinge on context. Free, one sitting.

25Sessions
beginnerLevel

Core competency stack

Start Learning for Free↓ 5 modules, 25 sessions below

Learning Path

25 sessions. Open a chapter to see every session, its brief, and the tools you'll use.

  • Tokens are not words

    Why text splits the way it does, and what that means for you.

  • How text becomes tokens

    Walking through tokenization on real text.

  • Code and non-English text

    Why some content costs far more tokens than others.

  • Counting tokens before you send

    Estimating size without guessing.

  • Why letter counting is hard

    A surprising weakness that falls out of tokenization.