PromptDiff
Compare LLMs across models. One API call.
Mar 24, 2026
Launch Date
Mar 25, 2026
First Tracked
About
AI Summary
PromptDiff is an AI tool that allows users to compare outputs from multiple language models (LLMs) in a single API call, providing details such as output, latency, tokens, and cost for various models from four providers. It requires no SDK and offers 100 free evaluations per month.
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.
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