From $29 per month · Free plan🇩🇪
Open-source platform from Berlin for prompt management, tracing and evals of LLM apps, as a cloud with an EU region or self-hosted.
Promptmetheus AI features and pricing (October 2026)
Prompt engineering IDE that builds prompts from blocks and compares them across 150+ models with test data and automatic evaluators.
Flat feeFree plan
from $29 per month
Pricing details
Forge playground free (local storage, OpenAI models). Single at $29 per month with a 7-day trial, Team at $99 per month for three users plus $19 per additional user.
What is Promptmetheus?
Promptmetheus is a browser-based IDE for prompt engineering. Users build prompts from reusable blocks, run them against many models and data sets, and evaluate the outputs, which suits developers and prompt engineers working on production prompts.
According to its terms, Promptmetheus is operated by an individual resident in Portugal. The IDE supports more than 150 large language models from 15 providers through their APIs. Prompts are composed of blocks such as context, task and examples, which makes variants easy to build. Test datasets inject dynamic context, automatic evaluators validate outputs, and the tool calculates costs and keeps a full version history. Results export to CSV, JSON, Excel and TXT. The Team plan adds a shared workspace with real-time collaboration.
Promptmetheus AI features and use cases
- Compares models on one promptThe same prompt runs against many models from different providers. Teams see differences in quality and cost before they commit to a model.
- Evaluates outputs automaticallyEvaluators check whether outputs meet defined criteria. Reliability problems surface across many runs, not just in a single test.
- Tests with varying dataDatasets feed different context into the same prompt template. Teams check whether a prompt holds up across realistic inputs.
What sets Promptmetheus apart
- Block-based prompt composition makes it easy to swap parts of a prompt.
- Built-in cost calculation per run across providers.
- Free playground that stores data locally in the browser.
Where Promptmetheus is strongest
Portugal Available internationally
Browser-based tool without a stated country focus, aimed at teams worldwide.
Questions to ask before you buy Promptmetheus
Prompts and test data go to the model providers whose API keys you use, so their data terms apply. The paid plans sync data to Promptmetheus's cloud; according to the security page, the database and backend run on DigitalOcean and the frontends on Vercel. The vendor names no storage region, no own certification beyond PCI compliance and no data processing agreement, and the contracting party is an individual, so ask before storing business data there.
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Questions about Promptmetheus
Is there a free version?
Yes. The Forge playground is free, stores data locally and supports OpenAI models.
What do paid plans cost?
Single costs $29 per month with a 7-day trial. Team costs $99 per month for three users plus $19 per additional user.
How many models can be tested?
More than 150 models from 15 providers, according to the vendor.
Promptmetheus update historyno updates yet
No changes recorded for Promptmetheus yet.
Changes the vendor made and confirmed user reports, each checked against the vendor's own pages. We review every tool monthly.
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