Usage & Limits
Claude usage limits
You were not stopped for sending too many messages. You were stopped for sending too many tokens — and most of them were probably messages you had already sent.
This page is part of the Usage & Limits hub, which covers the whole topic end to end.
Anthropic does not publish exact allowance numbers, and they move. What does not move is the mechanic, which is worth understanding because it explains almost every confusing thing about limits.
How the window works
- Rolling windows, not calendar resets. Allowances run over a rolling period — short windows measured in hours and a longer one measured in days. Nothing resets at midnight.
- Tokens, not messages. A one-line question in a thread carrying a 900-line file costs vastly more than the same question in a fresh conversation.
- Model-weighted. Heavier models draw down the allowance faster, which is why switching model can unblock you without waiting.
- Per person. Team seats do not pool. Your colleague’s spare capacity cannot be lent to you.
What burns a window fastest
| Pattern | Relative cost | Why |
|---|---|---|
| Long thread with pasted files | Very high | The whole history is re-sent every turn |
| Agentic / Claude Code runs | Very high | Many calls, each carrying tool output |
| Large document analysis | High | Big one-off input, often repeated |
| Several parallel sessions | High | Multiplies everything above |
| Short questions, fresh threads | Low | Almost nothing carried |
You just got cut off. Do this.
- Switch to a lighter model if the limit is model-specific. Much work does not need the heaviest one.
- Start a new conversation and paste a short summary instead of resuming the old thread. Resuming is what got you here.
- Buy extra usage if the work is time-critical — see extra usage.
- Do not immediately upgrade. Upgrading in the moment you are frustrated usually buys five times the capacity for the same wasteful pattern.
Why the limit feels inconsistent
Two Tuesdays with the same number of messages can produce completely different outcomes, which makes the whole system feel arbitrary. It is not: one of those Tuesdays you worked in four short threads, and the other you worked in one thread that grew all day. The second pattern can cost an order of magnitude more for identical output.
The structural fix
Treat a conversation as a working session with a scope, not as a place you live. When the task changes, start fresh and carry over a two-paragraph summary. Put standing rules into project instructions so you stop re-sending them. Paste the function, not the file.
For the full version of this, read tokens and context and the optimization playbook.