LettiB

LettiB is a web-based workspace that lets you compare answers from ChatGPT, Claude, Gemini, and Grok side by side — all using your own API keys. Instead of juggling tabs and losing context, you send one prompt and watch up to six models respond in parallel. The tool then helps you synthesize the strongest parts of each answer into a single, attributed response you can save and reuse. It's built for people who regularly use multiple AI models and want a single place to manage them.

How it works: you connect your own API keys from OpenAI, Anthropic, Google, Groq, and xAI (or any OpenAI-compatible endpoint). Keys are encrypted and stored in Supabase Vault. Once connected, you can run the same prompt across multiple models simultaneously. The Compare Mode shows all responses streaming live. The Synthesis feature merges the best ideas into one polished answer with source attribution. Project folders let you group related chats, compares, and syntheses, and Project Memory automatically tracks goals, decisions, and preferences so each new prompt starts smarter. Pricing is straightforward: a free tier with up to 2 models and 5 projects, then Pro ($15/month) and Power ($35/month) plans, plus a lifetime option for $79. All plans are BYOK — you pay the AI providers directly, and LettiB charges only for the workspace features.

Who benefits most? AI power users — researchers, developers, writers, and analysts who regularly compare outputs from different models. It's also useful for teams that need to organize AI work by project and maintain a searchable knowledge base. Real-world use cases include comparing model responses for research papers, synthesizing the best answer from multiple AI suggestions, and keeping all AI conversations organized by topic or project. If you're tired of tab chaos and want a privacy-focused way to use multiple AI models, LettiB offers a clean, straightforward solution.