About to change a prompt that's running in production? See what actually changes in your outputs — across realistic or redacted sample inputs, side-by-side, before you ship.
For indie AI builders, prompt engineers, and anyone shipping LLM-powered features who needs a 2-minute sanity check before rolling out a prompt edit.
1Paste your OLD prompt + NEW prompt
→
2Add 3–10 sample inputs
→
3See side-by-side outputs + heuristic diff labels
Loads a worked customer-support prompt change + auto-runs. ~5 seconds to "oh, that's what this does."
0 Configure
Demo Mode returns realistic sample outputs without making any API calls — try the full flow at zero cost. Switch to Real Mode when you're ready to run your own redacted or permitted prompts.
OpenAI API key
Model
1 Paste your two prompt versions
Old promptbefore change
New promptafter change
2 Add 3–10 sample inputs
Use realistic, redacted examples of inputs your prompt may receive in production. 5–10 cases gives a useful sample-case comparison.
3 Run the diff
or Ctrl + Enter
4 Export change-note
Saveable markdown record of the comparison + your reviewer notes. Paste into your team's review tool, commit message, or change-log.