Prompt Diff & Compare
Compare two prompt versions word by word with a token delta.
About the Prompt Diff & Compare
See exactly what changed between two prompt revisions: word, line or character level diffs, similarity score, added and removed characters, and the exact token delta using real BPE tables so you know what the edit costs per call.
Examples
Prompt revision
helpful assistant vs expert research assistantOutput
92.4% similar, +7 tokensKeyboard shortcuts
- Copy the main outputCtrl / ⌘ + Shift + C
- Download the resultCtrl / ⌘ + S
- Share this toolCtrl / ⌘ + Shift + S
- Reset the inputsAlt + R
- Open the tool search paletteCtrl / ⌘ + K
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Frequently asked questions
Read more
- How LLM tokens really work (and why your word count is a bad estimate)
BPE splits words, punctuation and whitespace into pieces. Here is how tokens are counted, why context windows overflow, and how to plan a prompt that fits.
Version 1.0.0 · Updated 2026-08-15 · Runs entirely in your browser