Testing ChatGPT and Claude usable chat length limits: about 300-500 A4 pages

I've been actively using OpenAI's ChatGPT, Microsoft Copilot, Claude, Gemini and Grok for testing AI's abilities in many different things, including software planning, architecture, and of course, coding.

I'm sure you are aware that all these chat AI tools have their limits on the context window. When you reach that, some AIs will just refuse to talk to you anymore, or they start to "compact" the earlier conversation history (for example Claude does this).

But you might also notice that if you just continue chatting, at some point, the conversation becomes very slow. Then, the question becomes: what is the usable limit?

My answer with the current technology: about 300 to 500 pages of text. For a long time already, I've taken backups of the most important conversations I make with AI. I do this simply by copy-pasting the whole conversation to Word, storing the chat URL, and saving to disk. This is also a great way to keep a copy of all your ideas, especially if you use AI for brainstorming like I often do.

Now, on the usable limits: at about 300 pages in Word (Word will happily paginate and count your pages), Claude starts compacting, ChatGPT start becoming slow, and Copilot can start refusing to continue ("You've hit your limit").

So, depending on your chat's nature and content, about 300 to 500 pages of A4's seems to be the usable limit. It's very long already but could be a bit longer in my opinion, as I easily reach these lengths in my AI chats.