xAI released Grok-1.5 with a 128,000-token context window and substantially stronger reasoning, closing the gap with frontier rivals. A vision variant, Grok-1.5V, added image understanding on April 12.

The release showed xAI could iterate quickly: five months after the Grok debut, the model was competitive on standard benchmarks. Musk promised Grok-1.5 would reach X Premium+ subscribers within days.

Grok-1.5 set up the bigger Grok-2 push later in 2024, when xAI aimed to move from catching up to leading.