Fix Claude Stuck in a Loop Repeating Answers

When using Claude (either via the web interface or the API), you may occasionally encounter a bug where the model gets stuck in an infinite loop. It might repeat the same sentence, rewrite the identical paragraph over and over, or regurgitate a specific block of code without moving forward.

This behavior, often referred to as a "repetition loop," occurs when the model's own previous output heavily skews its probability matrix. Because Large Language Models (LLMs) predict the next token based on preceding context, once a repetitive pattern is established in the chat history, the mathematical probability of continuing that pattern spikes dramatically. Here is how to diagnose and resolve this issue.

1. Start a Clean Chat Session The absolute fastest way to resolve a repetition loop is to abandon the current conversation and start a new one.

Because Claude relies on the active context window to generate responses, any repetitive text in the history acts as a "magnet" for future repetitions. Starting a new session wipes this history clean, resetting the probability weights back to baseline. If you need information from the previous chat, copy the useful parts of the history—excluding the repetitive loop section—and paste them into your new chat window.

2. Edit Your Prompt to Change the Path If starting a new chat is not an option (e.g., you have a complex setup that you don't want to lose), you can force-break the loop by editing your last prompt.

1. Hover over your last prompt in the Claude web interface and click the Edit icon.
2. Rewrite the prompt to ask the question differently. For example, add a direct constraint: "Do not use the word/phrase [repeated phrase] in your answer."
3. Click Save & Submit.

This forces the model to recalculate its generation path from a different starting point, bypassing the repetitive token sequence.

3. Inject a Negative Constraint or Pre-fill (API Users) If you are using the Anthropic API and experiencing repetitive loops, you have more granular controls to stop this behavior:

• Use Assistant Pre-filling: You can start the Assistant turn for Claude. If the model is stuck repeating "I apologize for the confusion, let me start over," pre-fill the assistant response with: "Here is the correct approach without any repetitive text: ". Claude will be forced to continue from your prompt rather than repeating its habitual opening.
• Implement System Prompts: Add a system prompt that explicitly penalizes repetition: "You must write concisely. Do not repeat phrases, loops, or previous sentences under any circumstances."
• Adjust Temperature: Repetition often happens when temperature is set too low (close to 0.0), forcing deterministic outputs. Raise your temperature parameter to 0.7 or 0.8 to introduce more randomness and break the loop.

4. Clear Browser Storage and Disable Translation Extensions Sometimes, the loop is not caused by the model itself, but by client-side browser issues or translation extensions.

1. Check if you have active browser translation extensions (like Google Translate) running on the Claude domain. These extensions can auto-translate the page in a way that tricks the Claude client into resubmitting the same input repeatedly.
2. Clear your browser cache and local storage for claude.ai.
3. Hard-refresh the page (Ctrl + F5 on Windows or Cmd + Shift + R on Mac) to reload the application state.

When to Escalate If Claude continues to loop even in entirely brand-new chats, across different devices, or when using different browsers, it is likely a temporary regression in the model weights on Anthropic's servers, or an ongoing platform incident. Check the official Anthropic status page. If the system is fully operational but the issue persists, submit a bug report directly through the Claude UI by clicking on your profile icon and choosing 'Support' or 'Help'.