Promptmetheus is a prompt engineering IDE built for systematically composing, testing, and optimizing LLM prompts rather than iterating blindly inside a chat interface. It gives direct access to 150+ language models across 15+ providers, including Anthropic, OpenAI, Google DeepMind, and Mistral, all from one workspace.
Automatic Evaluators score prompt outputs against defined criteria, and built-in Cost Calculation tracks spend across models and providers before committing to production use – turning prompt design into a measurable, repeatable engineering process instead of guesswork.
Promptmetheus targets developers, prompt engineers, and teams building LLM-powered products who need to compare models and iterate rigorously. Playground: free, single user, OpenAI models only. Single: $29/month. Team: $99/month with 3 included users, $19/month per additional user. 7-day free trial.
Promptmetheus has no advertised paid tier. Among the 75 priced tools we list in AI Infrastructure & Agent Tooling, the median entry price is $29 a month.
54% of AI Infrastructure & Agent Tooling tools in the directory offer a free tier, and this is one of them.
Compared against every priced listing in AI Infrastructure & Agent Tooling, recalculated as the catalogue changes. Method and the full market breakdown are in our AI tool pricing study.
One API routes to 500+ AI models across 50+ providers – OpenAI, Anthropic, Google, AWS, Cohere and more – with automatic fallback if a provider goes down, no markup on the underlying cost.
Node-based infinite canvas for running, comparing and chaining prompts across OpenAI, Anthropic and Replicate models, with a live demo and a paid Pro tier.
Single OpenAI-compatible endpoint for calling GPT, Claude, Gemini, and 400-plus other AI models.
Guardrails, evaluation and red-teaming for LLM apps, with judge models fast enough for runtime.
