How text becomes tokens
The sentence “Please send the minutes of the meeting to all partners by Friday.” became 13 tokens with OpenAI’s o200k_base tokenizer: Please, send, the, minutes, of, the, meeting, to, all, partners, by, Friday, and the full stop. Common words are one token each. Rarer words split into pieces: “unbelievably” became three tokens, un, bel and ievably. Numbers, codes and names split into short fragments.
On English prose, we counted 1.30 to 1.35 tokens per word, using two OpenAI tokenizers and Qwen3’s on the abstracts of the Transformer paper and the Llama 3 paper listed below (335 words). That is about 5 characters per token. Meta reports 3.94 characters per token for the Llama 3 tokenizer on a sample of English. A safe working range is 4 to 5 characters, or about 1.3 tokens, per English word.