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Token

The unit of input and output for an LLM. A token is roughly 3-4 characters in English (e.g. "hello" is one token, "hellos" is two). Models charge per input and output token. Note: Claude Opus 4.7 uses a new tokenizer that produces ~1.35x token count for the same text vs Claude 4.6.

How it works

Tokenisation breaks text into sub-word units using a vocabulary the model was trained on. Common tokens (the, of, ing) are single tokens; rare or specialised words may take multiple tokens. Pricing scales with token count, so efficient prompting matters at scale.

Example

A 1,000-word page is roughly 1,300-1,500 tokens. At Claude Opus 4.7's $5/M input rate, that's $0.0065-0.0075 per page processed.

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