Elon Musk's artificial intelligence company, xAI, is intensifying the competition by testing a new version of its model, dubbed Grok 4.20. In a post on the social media platform X, Elon Musk teased a potential late August launch, setting the stage for a direct showdown with OpenAI's highly anticipated GPT-5.
xAI, which was founded by Musk in March 2023, has been moving at a rapid pace. The company unveiled Grok-1 in November 2023, followed by Grok-1.5 in March 2024 and Grok-2 in August 2024. The most recent major upgrade, Grok 4, was released in July 2025. Musk has already claimed that Grok 4 is superior to GPT-5, stating, “Grok 4 Heavy was smarter 2 weeks ago than GPT5 is now and G4H is already a lot better.”
The Grok 4.20 announcement comes as OpenAI is rolling out GPT-5. Officially released on August 7, 2025, GPT-5 unifies OpenAI's most advanced reasoning and multimodal capabilities into a single model. This model aims to reduce hallucinations and improve instruction following, while showing strong performance in areas like writing, coding, and health. For developers, GPT-5 is offered in three sizes (gpt-5, gpt-5-mini, and gpt-5-nano) via the API, providing flexibility between performance, cost, and latency.
On its side, Grok has already demonstrated competitive performance. Grok-2, released in August 2024, showed significant improvements over Grok-1.5 and achieved competitive performance levels in academic benchmarks. Specifically, Grok-2 outperformed GPT-4 Turbo and Claude 3.5 Sonnet in various metrics, including math competition problems (MATH), general knowledge (MMLU), and visual math reasoning (MathVista). Grok-2 also introduced image generation capabilities, with apparently fewer restrictions than competitors like DALL-E and Gemini.
Musk has emphasized that xAI's goal is to be "maximally truth-seeking." This philosophy has led to some controversial responses from Grok, but also a commitment to open-sourcing. In August 2025, Musk announced his intention to make Grok-2 open source, keeping his promise to release the previous version whenever a new model is launched. This strategy contrasts with OpenAI's more closed approach.
With Grok 4.20 in testing and GPT-5 already available, the competition between xAI and OpenAI is set to define the next phase of AI evolution. Users and developers are watching closely as both companies push the boundaries of what is possible in the field.