wow. Elon Musk just cofirmed Grok 4.5 launching tomorrow.
Some details that we know so far about Grok 4.5 from various reports.
• Grok 4.5 is built on xAI’s V9 foundation model with 1.5T parameters.
• That makes it about 3x larger than v8-small, which currently serves production traffic on X.
• V9 pre-training was completed on May 26, 2026.
• Cursor coding data was added after pre-training through supplemental training.
• Reinforcement learning is still ongoing.
• xAI is planning monthly new-model releases trained from scratch through the end of 2026.
• Grok 4.3 remains the current public API model on Amazon Bedrock.