Grok charges $20/month for basic access, $50/month for premium features, with a...

https://astro-wiki.win/index.php/What_Are_the_Grok_4_Heavy_Benchmark_Scores_Mentioned_for_Heavy%3F

Grok charges $20/month for basic access, $50/month for premium features, with a cap of about 10 prompts every 2 hours to manage usage. There’s no free trial, so you’ll want to be sure before subscribing