Microsoft adds xAI's Grok 4.1 fast to Copilot Studio
Microsoft just dropped xAI's Grok 4.1 Fast into Copilot Studio for US developers, starting February 19, 2026.
This new AI model is all about faster reasoning, handling huge chunks of info at once, and running complex workflows—though it doesn't do images.
It's part of Microsoft's push to give developers more powerful AI tools.
Grok 4.1 Fast can process entire document sets
Grok 4.1 Fast can process entire document sets thanks to its massive 2 million-token context window—which can dramatically simplify prompt engineering and RAG, though retrieval strategies may still be needed for cost or latency reasons.
It also cuts down on those weird "hallucination" errors by two to three times compared to older models, and it's quicker and cheaper to use.
You'll need to opt in if you want this upgrade (it's off by default).
No worries about privacy: your data isn't used for training, and it runs under strict enterprise security terms.