8d ago

xAI completed training of its 1.5 trillion parameter Grok V9 foundation model, which Elon Musk described as a major upgrade over the 0.5 trillion parameter Grok V8 now running as version 4.3

Public release expected in three to four weeks after fine-tuning.

0
Original post

We are improving the 0.5T Grok foundation model V8 (public version 4.3) every few days. The 1.5T V9 just finished training (incorrectly called pre-training) and is a major upgrade. Next, we are adding the Cursor data in supplemental training (others call this mid-training), then SFT and RL. About 3 or 4 weeks to release. This will be a banger.

12:33 AM · May 17, 2026 View on X

🚀🔜

Elon MuskElon Musk@elonmusk

We are improving the 0.5T Grok foundation model V8 (public version 4.3) every few days. The 1.5T V9 just finished training (incorrectly called pre-training) and is a major upgrade. Next, we are adding the Cursor data in supplemental training (others call this mid-training), then SFT and RL. About 3 or 4 weeks to release. This will be a banger.

7:33 AM · May 17, 2026 · 441.4K Views
7:38 AM · May 17, 2026 · 6.2K Views

The new 1.5T version of Grok arrives in June. Lately, I use 4.3 increasingly for research, search, and sourcing news. I like it. It thinks differently.

Elon doesn't mention it in this post, but he also has big 6T and 10T variants in training.

Elon MuskElon Musk@elonmusk

We are improving the 0.5T Grok foundation model V8 (public version 4.3) every few days. The 1.5T V9 just finished training (incorrectly called pre-training) and is a major upgrade. Next, we are adding the Cursor data in supplemental training (others call this mid-training), then SFT and RL. About 3 or 4 weeks to release. This will be a banger.

7:33 AM · May 17, 2026 · 441.4K Views
1:17 PM · May 17, 2026 · 27.2K Views

The new 1.5T version of Grok arrives in June. Lately, I use 4.3 increasingly for research, search, and sourcing news. I like it. It runs in a team of four, and it thinks differently.

Elon doesn't mention it in this post, but he also has big 6T and 10T variants in training.

Elon MuskElon Musk@elonmusk

We are improving the 0.5T Grok foundation model V8 (public version 4.3) every few days. The 1.5T V9 just finished training (incorrectly called pre-training) and is a major upgrade. Next, we are adding the Cursor data in supplemental training (others call this mid-training), then SFT and RL. About 3 or 4 weeks to release. This will be a banger.

7:33 AM · May 17, 2026 · 441.4K Views
1:05 PM · May 17, 2026 · 1.5K Views

@elonmusk @orcdev oh fuck yes 🔥🔥

Elon MuskElon Musk@elonmusk

We are improving the 0.5T Grok foundation model V8 (public version 4.3) every few days. The 1.5T V9 just finished training (incorrectly called pre-training) and is a major upgrade. Next, we are adding the Cursor data in supplemental training (others call this mid-training), then SFT and RL. About 3 or 4 weeks to release. This will be a banger.

7:33 AM · May 17, 2026 · 441.4K Views
8:33 AM · May 17, 2026 · 1.9K Views

@elonmusk @brivael @orcdev 🚀

Elon MuskElon Musk@elonmusk

We are improving the 0.5T Grok foundation model V8 (public version 4.3) every few days. The 1.5T V9 just finished training (incorrectly called pre-training) and is a major upgrade. Next, we are adding the Cursor data in supplemental training (others call this mid-training), then SFT and RL. About 3 or 4 weeks to release. This will be a banger.

7:33 AM · May 17, 2026 · 441.4K Views
7:58 AM · May 17, 2026 · 1.5K Views

@elonmusk @orcdev any ETA?

Elon MuskElon Musk@elonmusk

We are improving the 0.5T Grok foundation model V8 (public version 4.3) every few days. The 1.5T V9 just finished training (incorrectly called pre-training) and is a major upgrade. Next, we are adding the Cursor data in supplemental training (others call this mid-training), then SFT and RL. About 3 or 4 weeks to release. This will be a banger.

7:33 AM · May 17, 2026 · 441.4K Views
9:58 AM · May 17, 2026 · 2.5K Views
xAI completed training of its 1.5 trillion parameter Grok V9 foundation model, which Elon Musk described as a major upgrade over the 0.5 trillion parameter Grok V8 now running as version 4.3 · Digg