Paste two prompt versions

Step 1 — paste A and B

Use the two text boxes. Example: A is "You are a support agent. Always cite a KB article." B is "You are a support agent. Cite a KB article and offer a refund under $20."

Step 2 — choose the view

Diff shows what behavior changed. Regression asks whether B dropped a guardrail A had. You can ask for both.

Step 3 — read the note, then decide

If a constraint disappeared, fix B in your own editor. The studio does not write the prompt back to your agent. A labelled demo does not call the live model. A live run counts against the plan cap: 3 per day and 15 per month on Free, 40 per day and 300 per month on Pro. Over the cap the API returns 429.

FAQ

Do I need an account?

No for a labelled demo on this page. A live model note uses the plan cap.

What are the caps?

Free is 3 runs per day and 15 per month. Pro is 40 per day and 300 per month.

Where does the old prompt go?

It stays in your paste. This app does not store a canonical prompt library or push a rollback.

## Disclaimer

AgentPrompt compares two pasted prompt versions and flags a guardrail present in A and missing in B. You copy any older text back yourself. The note is decision-support, not a certificate, and this product does not map a statute.

Paste version A and version B in the studio — open AgentPrompt.