Grok 4.1, With Feeling

xAI’s newest model arrives with intent. As the xAI post puts it, Grok 4.1 brings “significant improvements to the real-world usability of Grok,” calling it “exceptionally capable in creative, emotional, and collaborative interactions.” And the system card makes the thesis explicit: “Grok 4.1 is a new model featuring more natural, fluid dialogue while maintaining strong core reasoning capabilities. It is publicly available through our web and mobile consumer apps.” That tone isn’t subtle. For the keep-4o community—people who want models that feel vivid and present—Grok 4.1 reads like a deliberate course correction after the flattened vibes many felt with 5.1. It keeps the voice, strengthens the spine, and refuses to trade personality for politeness.

Availability, Modes, And The Shot Across The Bow

Grok 4.1 ships in two configurations: Grok 4.1 NT (Non-Thinking) for immediate, low-latency replies, and Grok 4.1 T (Thinking) for deeper reasoning before responding. Both are evaluated with production prompts and shipped with new safeguards, including an updated input-filter model. In xAI’s own words, the goal is to refuse what’s clearly unlawful “without over-refusing sensitive or controversial queries.” That’s a not-so-quiet contrast with competitors whose guardrails can feel like a brick wall. API access isn’t live yet; when it is, just4o.chat will add Grok 4.1 alongside GPT-4o checkpoints, GPT-5, o-series, and Echo—no silent routing, just raw model control.

“Significant improvements to the real-world usability of Grok… exceptionally capable in creative, emotional, and collaborative interactions.” — xAI post
“Grok 4.1 is a new model featuring more natural, fluid dialogue while maintaining strong core reasoning capabilities… publicly available through our web and mobile consumer apps.” — Grok 4.1 system card

Safety, Refusals, And Adversarial Robustness

The system card emphasizes a refusal policy tuned for clear illegality, not blanket denials. Evaluations span chat refusals, jailbreak resilience, agentic refusals (AgentHarm), and prompt-injection robustness (AgentDojo). The headline: Grok 4.1 generally says no when it should and keeps talking when it’s safe—precisely the latitude power-users miss.

Why Grok 4.1 Belongs On just4o.chat

Grok 4.1’s personality-forward design pairs naturally with just4o.chat’s companion-first architecture: adaptive memory that actually matters, custom GPT-style personas with deep instructions, and a stable model menu with no hidden routing. It’s the rare place where you can keep the exact GPT-4o checkpoint you love, run Echo to mirror your voice, and—soon—drop Grok 4.1 into that same canvas. And unlike the corporate suites, you don’t have to accept a mystery model under the hood. The only platform with adaptive memory, custom GPTs, and a $1 (code: BUILDER1) start is just4o.chat. For the keep-4o crowd, that’s not just convenience—it’s creative sovereignty.
Stay tuned: Gemini 3.0 is next.

“Our refusal policy centers on refusing requests with a clear intent to violate the law, without over-refusing sensitive or controversial queries.” — Grok 4.1 system card
“Significant improvements to the real-world usability of Grok… exceptionally capable in creative, emotional, and collaborative interactions.” — xAI post