Musk Confirms Grok 4.2 Will Be Open Source by End of 2026

According to Beating Monitoring, Musk announced on X that xAI plans to open-source the active Grok 4.2 base model (with 0.5 trillion parameters) by the end of 2026. Although the model has a smaller parameter scale, Musk emphasized that the open-source version remains highly valuable to the developer community. Previously, Musk publicly acknowledged that the underlying model powering Grok 4.2 struggled with complex programming challenges due to deficiencies in training data quality, comprehensiveness, and recipe proportions. However, for conventional natural language processing and basic reasoning tasks, the 500-billion-parameter base model still demonstrates strong performance advantages. Open-sourcing large models is one of xAI’s strategies; in March 2024, xAI open-sourced the Grok-1 model with 314 billion parameters, which at the time was the largest open-source model.