OpenAI does not publish a fixed number or size limit for ChatGPT memory, and its Memory help article says there is no separate storage limit for what ChatGPT can reference through chat history.
As of November 11, 2026, ChatGPT memory draws on past chats, saved memories, custom instructions, saved files and connected apps, depending on plan and region. Memory does not keep every detail; ChatGPT decides what is relevant. Saved memories are stored separately from chat history, and you manage them under Settings, Personalization, Memory.
The “Chat memory full” or “Context window full” notice on the Free plan is a different limit. According to OpenAI, it means the current conversation has filled up. Deleting saved memories will not free space in that chat; start a new chat instead, optionally with a summary, or upgrade if the notice offers it.
Related: What is the ChatGPT context window?, ChatGPT usage limits and Does ChatGPT train on your data?
Source: OpenAI Help Center, Memory in ChatGPT; OpenAI Help Center, Why does ChatGPT say Chat memory full?
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