Grok

Grok is the model family from xAI, Elon Musk's AI company, used through the Grok app and inside X, where it can pull on real-time posts. It started as the chatbot on X with a looser, more irreverent style, and has grown into a frontier model that competes on reasoning and coding. It's proprietary, though xAI has open-sourced some older versions.

Its signature is the tie-in to X: live access to what's being posted right now, which makes it handy for current events and public sentiment. It comes in the usual tiers, and xAI has been pushing it toward coding and agent work alongside plain chat.

Grok shines when real-time information matters, since its live view into X is something the other big models don't have out of the box, useful for breaking news or gauging the mood on a topic. It's also a fine general default if you're already in the X ecosystem.

The usual closed-model tradeoffs apply: metered use, and data going to xAI. And the looser style cuts both ways, less filtered can mean more useful or more off, so check its output like you would any model's.