Context Window Visualizer

A context window is the maximum number of tokens an LLM can process in a single request. This includes your system prompt, conversation history, and the model's response. If your input exceeds the context window, the API will return an error.

At 75% context usage, some models may start to show degraded performance on long-context tasks. It's a heads-up to consider whether you need all that context, especially if you need room for the model's response.

If your text exceeds the model's context window, the API call will fail. The tool shows you exactly how many tokens you need to cut to fit within the limit.

We take the remaining context window capacity and divide by the token count of your current text. This tells you approximately how many more messages of similar length could fit.

Google's Gemini 2.5 models support up to 1 million tokens of context, significantly more than most other models. This is useful for processing very long documents or extended conversations.