The iteration loop for prompt engineers.
Version, test, and compare across models.
Side-by-side comparison
Built for the iteration loop
Every change is a numbered, immutable version. Roll back, compare, or branch your prompts at any time.
Run your prompt against Gemini, Claude, and GPT-4o in one click. Real outputs, real latency, real token costs.
Invite teammates with granular roles — owner, editor, or viewer. Ship better prompts together.
One click, every model
# Select a prompt version version v3 Customer Support Reply Generator # Run your test case against all models compare --test "Angry customer about delayed shipping" # Results (parallel, ~1.2s total) ✓ Gemini 2.5 Flash 312ms 284 tokens ✓ Claude Sonnet 4.6 891ms 197 tokens ✓ GPT-4o 1204ms 312 tokens
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