How to define user message size limit for particlular prompt?

[lofti198]

My case is content summarization: I provide text and chatgpt to summarize it. How can define user message size limit for this particular prompt, ideally considering language of the user message (as I assume it can also affect)? I mean, I want to identify limit before sending the request, to be able to reduce the content (user message) in advance if it is needed. I can do that using just assumable token based calculation , but maye chatgpt.net itself has some special methods for this purpose?

Another question is - is the token size the same for different requests (with the samу physical amount of symbols)? For example I can ask to summarize text, which is (as I guess) more complicated operation, than lets say to extract first sentence for each text paragraph.