Prompt Diff Checker

Compare two prompt versions line by line, with added/removed highlights and a similarity score.

When you are iterating on a prompt, the thing you lose first is what the previous version actually said. This tool compares two versions line by line — additions in green, removals in red — and reports a similarity score. Switch to the duplicate view to see which lines repeat, useful for spotting a prompt that has been stacked up from several sources.

How to use it

1. 1Paste the old version on the left, the new one on the right (swap them and the result reads backwards).
2. 2Scan the green and red rows to confirm the change matches your intent.
3. 3For duplicate detection, switch modes and put the text in either pane.

FAQ

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