Gemini and other generative AI models process input and output at a granularity
called a token.
About tokens
Tokens can be single characters like z or whole words like cat. Long words
are broken up into several tokens. The set of all tokens used by the model is
called the vocabulary, and the process of splitting text into tokens is called
tokenization.
For Gemini models, a token is equivalent to about 4 characters.
100 tokens is equal to about 60-80 English words.
When billing is enabled, the cost of a call to the Gemini API is
determined in part by the number of input and output tokens, so knowing how to
count tokens can be helpful.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-21 UTC."],[],[],null,["# Understand and count tokens\n\nPython JavaScript Go\n\n\u003cbr /\u003e\n\nGemini and other generative AI models process input and output at a granularity\ncalled a *token*.\n\nAbout tokens\n------------\n\nTokens can be single characters like `z` or whole words like `cat`. Long words\nare broken up into several tokens. The set of all tokens used by the model is\ncalled the vocabulary, and the process of splitting text into tokens is called\n*tokenization*.\n\nFor Gemini models, a token is equivalent to about 4 characters.\n100 tokens is equal to about 60-80 English words.\n\nWhen billing is enabled, the [cost of a call to the Gemini API](/pricing) is\ndetermined in part by the number of input and output tokens, so knowing how to\ncount tokens can be helpful."]]
