Grok offers two paid plans starting at $20/month for basic access and $50/month...

https://oliviasinsightfulthoughts.novacrestiq.com/posts/what-is-the-context-window-for-grok-4.3-1m-or-500k-a-deep-dive-into-grok-model-context-and-pricing

Grok offers two paid plans starting at $20/month for basic access and $50/month for advanced features. Both limit users to about 10 prompts every 2 hours. There’s no free trial, so you’ll need to commit upfront to test the service