PromptFast is a subscription-based SaaS playground for prompt engineers and AI developers. It provides an isolated, fast, multi-model environment to test, compare, and track prompts — without touching your application infrastructure.
- Run a prompt against 13+ models across OpenAI, Anthropic, and Google simultaneously
- See real-time token-by-token streaming responses
- Track exact cost per run with model-specific pricing
- Upload PDFs, CSVs, DOCX files as document context
- Keep a full history of every experiment, reloadable in one click
- Compare two models side-by-side with parallel execution
