Grok (on X, free tier)

Free to use on X/grok.com; the vendor doesn't publish a fixed figure, and community testing puts the rolling limit at roughly 10 messages per 2 hours

As of 2026-06, xAI dropped separate daily limits per product line in favor of a unified weekly shared usage pool. As of 2026-03, image/video generation (Grok Imagine) has been moved behind the paid SuperGrok subscription.