Resource
Compare Two Versions of a Prompt
See exactly what changed between v1 and v2 of a prompt — added, removed, and modified instructions, plus whether the revision reduced or introduced risk.
What Changed in My Prompt? A Revision Diff
When a prompt's output suddenly shifts, the first question is what changed in the prompt. A diff answers it in seconds — additions, removals, and edits, itemized.
Overview
The usual debugging story: a prompt that produced reliable output starts behaving differently, and the only suspect is an edit someone made along the way. Re-reading the prompt won't surface the change — you remember the intent, not the wording. Diffing the current version against the last known-good one shows the exact instructions that were added, removed, or reworded, and flags whether any of them moved a risk signal. The loaded pair reproduces this scenario: a small 'harmless' edit that actually dropped a constraint.
How to use this resource
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Diff the loaded pair
Version B looks like a harmless extension — it adds milestones with dates. Run the diff.
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Find the silent removal
The 'do not mention internal discussions or unconfirmed timelines' constraint is gone — and B now asks for dates, which that constraint used to guard.
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Read the risk changes
Removed constraints register as an output-control decrease. That's the regression the edit's author never noticed.
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Apply to your incident
Paste the last known-good version as A and the current one as B — the suspect edit is in the removed or modified list.
Why This Works
- Memory recalls a prompt's intent, not its wording — diffs recall the wording
- Silent constraint removals are the most common cause of 'the prompt suddenly got worse'
- Itemized changes turn 'something is off' into a specific, fixable edit
Best for
- Prompts where output quality regressed after an edit
- Shared prompts edited by more than one person
- Guardrail-heavy prompts where silent removals are costly
Not for
- Deciding which of two prompt drafts to adopt — that's the Prompt Comparator
- Cleaning repetition out of one prompt — that's the Prompt Cleaner
Use cases
- Debugging why a stable prompt's output suddenly changed
- Auditing an edit a teammate made to a shared prompt
- Verifying a 'small tweak' didn't remove a guardrail
FAQ
How does the diff catch a constraint that a 'small tweak' silently removed?
It itemizes additions, removals, and edits, so a dropped line surfaces in the removed list even when the edit looked like an extension. In the loaded pair, version B reads as a harmless add (milestones with dates) but quietly deleted "do not mention internal discussions or unconfirmed timelines" — the constraint that used to guard the very dates B now requests.
How do I point the diff at my own prompt regression?
Paste the last known-good version as A and the current one as B, per the workflow's final step; the suspect edit lands in the removed or modified list. The diff recalls the wording your memory doesn't, and flags removed constraints as an output-control decrease — but it compares two prompts, it doesn't run them or confirm the fix.
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Prompt Version Diff
Diff two versions of the same prompt — added, removed, and modified instructions, plus risk changes.