Langfa.st is a fast and minimal playground for testing and refining AI prompts. It supports over 50 large language models, including OpenAI, Anthropic, Mistral, Cohere, Google, and others — all available instantly without setup. You can insert variables, use Jinja2 templating, and compare outputs across models. There’s no need to sign up or bring your own API keys — it works out of the box. Langfa.st was built to eliminate the friction of existing tools: complicated UIs, required credentials, or overpriced subscriptions. It gives AI teams and prompt engineers a clean, disposable space to experiment, debug, and iterate — all in one tab. Free to use. You only pay if you need more volume or power features.

Langfa.st is a fast and minimal playground for testing and refining AI prompts. It supports over 50 large language models, including OpenAI, Anthropic, Mistral, Cohere, Google, and others — all available instantly without setup. You can insert variables, use Jinja2 templating, and compare outputs across models. There’s no need to sign up or bring your own API keys — it works out of the box. Langfa.st was built to eliminate the friction of existing tools: complicated UIs, required credentials, or overpriced subscriptions. It gives AI teams and prompt engineers a clean, disposable space to experiment, debug, and iterate — all in one tab. Free to use. You only pay if you need more volume or power features.

AI Chatbot Online is an immersive platform that lets fans chat with AI-powered personas inspired by beloved shows, games, books, and other stories. It bridges the gap between imagination and interaction, allowing users to create and fully customize AI chatbots with unique personalities, voices, and backstories. Every conversation is designed to feel natural, emotionally engaging, and true to the persona’s traits. Whether you want to relive iconic moments, explore “what if” scenarios, or invent entirely new adventures, AI Chatbot Online delivers a seamless and intuitive experience. With powerful customization tools and a vibrant community, it’s the perfect space to connect with the worlds and characters you love—anytime, anywhere.

AI Chatbot Online is an immersive platform that lets fans chat with AI-powered personas inspired by beloved shows, games, books, and other stories. It bridges the gap between imagination and interaction, allowing users to create and fully customize AI chatbots with unique personalities, voices, and backstories. Every conversation is designed to feel natural, emotionally engaging, and true to the persona’s traits. Whether you want to relive iconic moments, explore “what if” scenarios, or invent entirely new adventures, AI Chatbot Online delivers a seamless and intuitive experience. With powerful customization tools and a vibrant community, it’s the perfect space to connect with the worlds and characters you love—anytime, anywhere.