Fix guide

"Conversation too long" in ChatGPT or Claude: how to continue in a new chat

By Prashant Kumar, updated 22 October 2026. About 5 minutes to read.

Long chats eventually hit a wall: ChatGPT shows "The conversation is too long, please start a new one", Claude says the conversation is too long to continue, or replies just get slow and start forgetting early details. Your old chat isn't lost. You just need to carry its context into a fresh one.

Why this happens

Every AI model can only "see" a limited amount of text at once, called its context window. Each message you send includes the conversation so far. When a chat grows past what the model can hold, the app either stops you or starts dropping the oldest parts.

• ChatGPT can show "The conversation is too long, please start a new one", and very long chats can become slow or stuck.
• Claude has a length limit per conversation, separate from its usage limit. Claude's help center explains the difference. If you've hit the usage limit instead, see this guide.

The old conversation stays in your history. You can still scroll and copy from it. The goal is a new chat that starts with the right context.

Fix 1: a handoff summary

If the old chat still accepts one more message, ask it to write a brief for the next chat:

We are moving to a new chat because this one is too long. Write a handoff
brief: my goal, key facts and decisions, what we tried and the results
(keep exact errors), the current state, and the next step. Keep code,
file names and numbers word for word.

Open a new chat in the same app, paste the brief and add: "Continue from this brief. First confirm the task and where we are."

If the old chat refuses every message, select a large part of the conversation, copy it and use Fix 2's paste option instead.

Fix 2: a fresh chat with mcosec.ai

mcosec.ai works even when the chat won't accept another message, because it reads the page instead of asking the AI.

1. Open the long chat and click the mcosec.ai icon. Press Read this chat.
2. Choose Short or Standard. Older messages are condensed, while your first message, the latest messages and the code are kept. The token meter shows how much smaller it got.
3. For the destination, pick the same AI (for example ChatGPT again) and press Copy and continue. A new chat opens with the compacted version in the message box. Press Send.

If reading the page ever fails, open Or paste the chat yourself, paste the text, and press Compact this chat.

Fix 3: projects and custom instructions

For work that lasts weeks, put what never changes (your stack, writing style, goals) into the app's own long-term settings, so every new chat starts with it:

• ChatGPT: custom instructions, memory, or a Project with files.
• Claude: a Project with instructions and files.

Then each new chat only needs the current state, which keeps it short.

How to avoid it next time

• One chat per task. Start a new chat when the topic changes.
• Hand off early. Move to a fresh chat when replies slow down or start forgetting things, not after the error.
• Don't paste huge files into the chat. Attach them, or paste only the relevant part.
• Keep a running brief. Every so often, ask for an updated "state of the work" summary you can reuse.

Questions