What is the maximum number of tokens GPT-4o supports when processing promt?

Hello. What is the maximum number of tokens GPT-4o supports when processing promt? I sent it large files to read, but he was only able to read part of it. When checking how much it read, it turned out to be about 16-20k tokens (checked via platform. openai. com/ tokenizer), but the AI ​​likes to lie, so I don’t know for sure at what point it stopped reading. I have a Plus subscription for $20 per month.

My question is not about the API, but about chatgpt. com

P.S: For some reason I can’t insert links, so I put spaces