Free tool
Stop token overflow.
Measure your text length in tokens and see exactly how much room you have left in the context window of your favorite LLM.
Est. Tokens
0
Limit
128,000
0.00% used128,000 left
01
Context
Understanding context windows
The limit on how much a model can 'remember' at once.
What is a context window?
The context window is the maximum number of tokens a model can process in a single request. If your prompt exceeds this, the model will either error out or truncate the beginning of the conversation.
The Token Gap
A common mistake is thinking in characters or words. Tokens are chunks of characters, and the exact ratio varies by model.