Count tokens for GPT-4o mini and estimate API cost before you send a request. Counts run the exact o200k_base (OpenAI) in your browser.Your text never leaves the browser.
Paste your prompt into the counter on this page. GPT-4o mini uses the o200k_base (OpenAI), and the count runs in your browser with the same published tokenizer, so the number matches what the API reports for plain text.
How much does GPT-4o mini cost per token?
GPT-4o mini costs $0.15 per 1 million input tokens and $0.60 per 1 million output tokens, based on official OpenAI pricing checked 2026-08-11.
What is the context window of GPT-4o mini?
GPT-4o mini has a context window of 128,000 tokens, which is roughly 96,000 English words of combined prompt and response. The counter above shows how much of that window your text consumes.
Is this GPT-4o mini token count exact?
Yes. The page runs the o200k_base (OpenAI) in your browser, the same tokenization the OpenAI API applies, so counts are exact for plain text input.