Grok

xAI posted that Grok 4 is free for all users worldwide for a limited time, with Auto mode routing tougher prompts to Grok 4 and an “Expert” option to force it every time. The announcement also mentions generous but temporary usage limits so people can explore the full model during the promo window. Screenshots circulating show the in‑app banner and the Auto/Expert guidance alongside short clips of users trying it on coding and research tasks, which lines up with xAI’s push to get hands‑on comparisons against other flagship models.

Here’s how it works in practice. Opening Grok on X or the Grok app now defaults to Auto; simple prompts may run on a lighter path, but anything complex should escalate to Grok 4 without extra steps. Switching to Expert locks Grok 4 for every query, which power users will prefer if they don’t want the router second‑guessing. Expect rate limits—xAI calls them “generous,” but they’ll still cap heavy runs and high‑volume testing. The separate Heavy/“generative usage” options tied to paid tiers aren’t part of this free flip, so advanced multi‑agent features will still feel gated.

If the goal is a real‑world trial, try a small battery of tasks: a multi‑file code refactor, a math or data reasoning chain that needs tool use, and a long‑context research summary with citations. Run once on Auto, once on Expert, and note latency, correctness, and how often it asks for clarifications. Share failures too—router misfires and rate‑limit edge cases matter as much as wins when the promo ends.