Error messages

Your message will exceed the length limit. Try attaching fewer or smaller files or starting a new conversation.

Your message will exceed the length limit. Try attaching fewer or smaller files or starting a new conversation.

You try to send something big, usually with a PDF or a few files attached, and the Claude app stops you with:

Your message will exceed the length limit. Try attaching fewer or smaller files or starting a new conversation.

Without attachments the second sentence changes to Try shortening your message or starting a new conversation. Anthropic's troubleshooting article quotes an older form that ends "for this chat", and that's still the wording people search for. We found the current text in the claude.ai web code on September 25, 2026, where it's tied to an HTTP 413 answer (413 means "request too large").

How it differs from “chat is too long”

The app has two length messages and they come from different refusals. This one fires when the request as a whole is too large to accept, so it usually points at what you just added. The other, “This chat is too long to continue”, appears when the model reports that the whole prompt doesn't fit its context window (the most text it can read at once), and it points at the chat history and your connectors.

In practice both mean the same thing to you: there's too much in this turn. The fix depends on which part is big.

What to cut

Anthropic's article says the error means "your message is too long and needs to be shortened", and suggests:

• splitting the content into smaller chunks and sending them one at a time
• summarizing or pulling out the key sections before you send
• asking Claude to find the relevant parts first, then working on those
• starting a new conversation

A long PDF is the common culprit. For files you'll keep coming back to, a project is the better home: Anthropic's length-limits article says projects retrieve only the relevant parts of their files instead of loading every page into the chat.

When a one-word message fails

If “Hi” gets this error, your message isn't the problem. In a July 2025 report, someone installed an MCP server (a plug-in that gives Claude extra tools) and from then on every prompt, even “Hi”, came back with the "Try shortening your message" version. Each tool's definition travels with every message, and a server with many tools can take up much of the window. The same length-limits article says "Tools and connectors are token-intensive". Turn off the connectors this chat doesn't need and try again.

That surprised us, since the error's wording blames your message. But the size check covers everything sent with it.

Neighboring limits

Two siblings in the same part of the app code look alike but count something else. Your message will exceed the maximum number of files allowed per message. is about how many files you attached, and the fix is to spread them over several messages. The "maximum image count" version counts images, and the app says each PDF page counts as one image, so a long scanned PDF can trip it on its own.

If you hit length limits often in long chats, check that code execution is on. The troubleshooting article says that on paid plans with it enabled, Claude summarizes earlier messages as a chat nears the limit, so "most users will rarely encounter length limit errors". A very large first message can still hit one.