One workspace for every AI you use.
Compare GPT, Claude, Gemini, and Grok side by side. Merge the best answers into one. Organize everything into projects with memory.
BYOK · No credit card required · Free forever plan
Your AI work is scattered across 5 tabs.
ChatGPT in one tab. Claude in another. Gemini for that one thing. Notes in a doc you'll never find again. Every answer half-right, none of them together. LettiB pulls it all into one workspace — compare, synthesize, save.
Everything you need to run multi-AI workflows.
Six features. Zero context switching.
Connect your keys
Bring your own OpenAI, Anthropic, Google, or xAI keys. Your usage, your costs — zero markup.
AI Teams
Group your favorite models into reusable teams (e.g. 'Research Trio', 'Code Review Squad').
Compare Mode
Send one prompt to multiple models in parallel. See every answer side by side, in real time.
LettiB Synthesis
Merge the best parts of every response into one authoritative answer, scored and sourced.
Project folders
Organize chats, comparisons, and syntheses into projects. Build a knowledge base that compounds.
Project Memory
Capture goals, decisions, preferences, and facts. LettiB carries context from one prompt to the next.
Three steps. One smarter answer.
Connect
Add your provider API keys once. Encrypted at rest, only the last 4 chars ever leave the server.
Compare
Pick a Team, type your prompt, and watch every model stream their answer in parallel.
Synthesize
One click merges the best ideas into a single, rated answer saved to your project.
Simple, BYOK pricing.
You bring the keys. We bring the workspace. No usage markup, ever.
Free
Bring your own keys. Get the full workspace.
- BYOK — unlimited providers
- Compare up to 3 models at once
- 5 projects
- Synthesis (10 / month)
- 7-day history
Pro
For daily power users who live in multi-AI workflows.
- Everything in Free
- Compare up to 6 models at once
- Unlimited projects
- Unlimited Synthesis
- Project Memory
- Unlimited history & search
Power
Teams and prosumers running heavy comparisons.
- Everything in Pro
- Compare up to 12 models at once
- Custom AI Teams
- Shareable synthesis links
- Priority synthesis queue
- Priority support
All plans use your own provider API keys. You pay the providers directly for their usage.
Frequently asked.
Do you store my API keys?+
Yes — encrypted in Supabase Vault and decrypted server-side only when needed for a request. We never expose them to the browser, and you can revoke them anytime from Settings.
Whose API costs am I paying?+
Yours. LettiB is BYOK — you bring your own provider keys, and you pay the providers directly. We charge a flat monthly subscription for the workspace, with zero usage markup.
Which models are supported?+
OpenAI (GPT-5, o-series), Anthropic (Claude Sonnet & Opus), Google (Gemini), and xAI (Grok). Custom OpenAI-compatible endpoints work too.
What is a Synthesis?+
After a Compare, LettiB sends every model's response to a synthesizer model that produces one merged answer with the best of each — sourced, scored, and saved to your project.
Can I share my work?+
Yes. Any synthesis can be made public via a unique share link. Read-only — your account and other syntheses stay private.
Is there a free plan?+
Yes. The Free plan is BYOK, unlimited providers, with up to 3-model compare and 10 syntheses per month. No credit card required.
Try LettiB.
Bring your keys, run your first compare in under a minute, and see the difference a real multi-AI workspace makes.
Try LettiB