Apertus Chat (Public AI) is free, with no paid plan attached. K2 Think is free, with no paid plan attached. Both are listed under General Purpose Chatbots, so this is a like-for-like comparison. Neither is ranked above the other — Flocci carries no sponsored placement.
Apertus Chat (Public AI) is free, with no paid plan attached and is listed for chat directly on Apertus 1.5, the fully open Swiss model from ETH, EPFL and CSCS (released 2026-07-24). K2 Think is free, with no paid plan attached and is listed for MBZUAI/G42 chat app for the open Apache-2.0 K2 Think V2 reasoning model, served on Cerebras. Both sit in General Purpose Chatbots.
Neither — Apertus Chat (Public AI) and K2 Think are both free, so the choice comes down to capability rather than cost. Both entries list what they uniquely do above.
Choose Apertus Chat (Public AI) if you need chat directly on Apertus 1.5, the fully open Swiss model from ETH, EPFL and CSCS (released 2026-07-24); choose K2 Think if you need MBZUAI/G42 chat app for the open Apache-2.0 K2 Think V2 reasoning model, served on Cerebras. Flocci AI Tools does not rank one above the other — it shows both feature sets side by side and lets the requirement decide.
| Apertus Chat (Public AI) | K2 Think | |
|---|---|---|
| Pricing tier | Free | Free |
| Free to start | Yes | Yes |
| Category | AI Chat & Assistants | AI Chat & Assistants |
| Type | General Purpose Chatbots | General Purpose Chatbots |
| Listed capabilities |
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| Tags | apertus, swiss ai chat, apertus 70b, public ai chat, open swiss llm, free sovereign ai chat | k2 think, mbzuai k2, k2 think v2, free reasoning model chat, uae ai chatbot, open source reasoning ai |
| Website | chat.publicai.co | k2think.ai |
| Full page | Apertus Chat (Public AI) details → | K2 Think details → |
| Alternatives | Apertus Chat (Public AI) alternatives → | K2 Think alternatives → |