Stop copy-pasting prompts across ChatGPT, Claude, and Gemini. PromptDiff compares LLM outputs in one API call.
Send a prompt + pick models. Get back: output, latency (ms), tokens, and cost (USD) per model.
8 models, 4 providers:
- Claude Sonnet & Haiku
- GPT-4o & 4o-mini
- Gemini Pro & Flash
- Grok 3 & 3 Mini
No SDK needed. Works with curl, Python, TypeScript.
Free: 100 evals/month, no card. Built by a solo dev from Tokyo.
