What is a token?
Your first step toward understanding AI pricing
Key takeaway
A token is a small chunk of text that AI uses when reading and writing. AI usage charges depend on how many tokens it processes.
AI reads text in small chunks
Just as we break a sentence into words, AI processes text by dividing it into small chunks called tokens. Start with this basic idea.
The Japanese sentence “今日は良い天気です” (“The weather is nice today”) can be illustrated as roughly five chunks, or tokens. AI reads and writes in these units; the exact split depends on the model.
A rough rule of thumb is enough
The system counts tokens automatically, so you do not have to calculate the exact number yourself. The following examples give you a useful sense of scale.
A guide for Japanese text
One Japanese character is approximately 1–1.5 tokens. The ratio varies with kanji and kana.
One email
An email of around 400 Japanese characters is approximately 600 tokens.
One million tokens
A substantial amount of text: roughly five or six Japanese paperback books.
Think of tokens as grams of ingredients in cooking. Longer recipes and more dishes (text) need more ingredients (tokens), so the ingredient bill (usage cost) goes up.
Frequently asked questions
What is a token?
It is a small chunk of text that AI uses to read and write. For Japanese, one character is roughly 1–1.5 tokens.
How does that affect pricing?
Charges depend on the number of tokens, so longer text costs more. The system does the counting; you only need to remember that more text means higher usage charges.
Based on the official pricing pages of OpenAI and Google AI, as of June 2026. Prices, model names, and specifications can change; check current official information before deciding. Estimates use USD 1 = JPY 160 and approximately 1.5 tokens per Japanese character. They are illustrative Japan-market references, not quotations or estimates for English-language text. This series does not recommend any particular service. Contact sales to confirm current product pricing, delivery, warranty, and support for your country.
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