xAI Plans Limited Grok 4.8 Rollout for Bot Users This Week

xAI plans to begin a limited release of Grok 4.8 for Bot users later this week, Elon Musk said Nov. 10. The plan follows the model’s completed pretraining and moves it into another stage of development.

Musk said the model is now in reinforcement learning, and its evaluation scores have started to improve.

He cited the replacement of JAX and SGLang with C and C++ rewrites of the reinforcement learning and inference systems as one reason development took longer. The team also extensively cleaned up the supervised fine-tuning data, Musk said.

Musk described Grok 4.8 as substantially different from Grok 4.7, though he said it is not yet impressive. He said the model’s foundations are in place.