On 10 November 2026, Elon Musk (@elonmusk) replied on X to a request for a Grok 4.8 update:
We have dumped JAX/SGLang and rewritten the entire RL and inference stack from scratch in C/C++, which took some extra time.
Training (aka pre-training) is done. Lot of cleanup was needed on the SFT data to get that mostly right. Now, 4.8 is in RL and the evals are starting to climb. We will do a soft rollout to Bot users later this week and see how it goes.
Grok 4.8 will bear no resemblance to 4.7 (thankfully). It is not yet incredible, but, this time, the foundations are built right, so I expect it to evolve to be something special.
What was announced
From the @elonmusk post:
- The reinforcement learning (RL) and inference stack was rewritten from scratch in C/C++, replacing JAX/SGLang. The rewrite took extra time.
- Pre-training is complete. Cleanup of supervised fine-tuning (SFT) data was required.
- Grok 4.8 is now in RL. Evaluations are starting to climb.
- A soft rollout to Bot users is planned for later this week.
- The model will bear no resemblance to Grok 4.7. It is described as not yet incredible, with foundations built correctly this time, and expected to evolve into something special.
No release date beyond the soft rollout window, pricing, benchmark scores, context length, or availability details outside Bot users were stated.
Context
Grok 4.7 launched on 21 September 2026 as SpaceXSI’s frontier model for coding and knowledge work, available in Cursor, Grok Build, and the xAI API. A 30 October 2026 post by @elonmusk said Grok 4.8 would not be a disappointment and that the team was not optimising for benchmarks.
This 10 November note is a status update on training progress and a planned limited rollout, not a full public model announcement.
Limits of this report
This article reports only the statements in the 10 November 2026 @elonmusk post. It does not include model specifications, independent benchmark results, exact rollout timing beyond “later this week,” pricing, or any claims not present in the source. No x.ai news post or official company account confirmation of the soft rollout was available at the time of writing.