foundationPrompt Craftbeginner

token

/TOH-kun/

The basic unit of text that AI models process — roughly 3/4 of a word. Tokens determine cost, context limits, and processing speed.

Impact
Universality
Depth

A token is how AI models see text. Rather than reading word by word, models break text into tokens — fragments that are roughly 3/4 of a word on average. 'Unbelievable' might be three tokens: 'Un', 'believ', 'able'. Common words like 'the' are usually one token. This matters because everything in AI is priced and limited by tokens.

Context windows are measured in tokens (Claude has 200K, GPT-4 has 128K). API pricing is per-token. Response speed depends on tokens generated. When someone says 'I ran out of context,' they mean they hit the token limit.

Understanding tokens gives you practical superpowers: you can estimate costs, know when to summarize instead of dumping full documents, and understand why some prompts work better than others (shorter prompts leave more room for the response).

When to Use It

When discussing AI costs, context limits, prompt optimization, or debugging why a long conversation started losing quality.

Try This Prompt

$ Summarize this document to fit within 2000 tokens — I need to include it in a larger prompt.

Why It Matters

Token literacy is financial literacy for AI. Every wasted token costs money and displaces useful context.

Memory Trick

Think of arcade tokens — you have a limited number, each one lets you play a little more, and when they're gone, the game's over.

Example Prompts

How many tokens is this document? Will it fit in a single prompt?
Optimize this prompt to use fewer tokens without losing meaning
I'm hitting the context limit — summarize the earlier conversation so we can continue
Estimate the API cost for processing 10,000 documents at this token count

Common Misuses

  • ×Thinking 1 token = 1 word (it's roughly 0.75 words)
  • ×Confusing tokens with characters — they're different units entirely
  • ×Not realizing that both input AND output count toward token limits and costs

Related Power Words

A Mac app that coaches your AI vocabulary daily

Become a Better AI Communicator