Prompt capacity
Will this prompt fit the model?
Count a plain-text prompt locally, choose a tracked model, and see how much context it uses before you send it.
Context used
0%
Tokens0
Remaining0
Tracked limit0
Paste a prompt to check its size.
Runs locally in your browser. Your prompt is not uploaded.
FAQ
Prompt size questions
What does the prompt size checker measure?
It counts the text locally with the OpenAI o200k_base tokenizer and compares that count with the selected model's tracked context window.
Will the provider count be identical?
Provider APIs can add system instructions, tools, chat wrappers, or multimodal formatting. Use this as a plain-text planning check and verify the provider's request format.