Two new xAI Grok models leaked, Grok 4.20?

Two new xAI models are now leaked on OpenRounter under the Stealth segment, which are expected to be Grok 4.2 (Grok 4.20) with new upgrades over Grok 4 and Grok 4 Fast.

OpenRouters has recently listed two stealth models – Sherlock Think Alpha and Sherlock Dash Alpha. The first is a frontier model and a mini model of what we can speculate from previous xAI launches.

According to the details page, the Sherlock Think Alpha is a non-reasoning model that excels at tool calling with a 1.8 million context window and multimodal support. On the other hand, the Sherlock Dash Alpha could be a speed-optimized version.

OpenRouter’s Sealth models are a series of experimental, pre-release large language models (LLMs) hosted on the OpenRouter platform, released under pseudonymous or fictional provider names to enable blind testing and unbiased user feedback.

That said, the models aren’t officially affirmed by xAI, but previous information suggests that they might belong to the Grok maker.

Two xAI Grok Models listed on OpenRouter Stealth

Grok 4.20

Soon after the Grok 4 release in July, Elon Musk, Founder and CEO of xAI, started teasing an incremental model update as Grok 4.20, calling it “Inevitable”. He predicted the Grok 4.20 to be released in August, and that didn’t happen. A major feature of this new model could be code generalization.

The xAI leader confirmed that xAI’s V7 foundation model has already finished training and it’s natively multimodal, while the Grok 4 and Grok 4 Fast are based on V6. It is capable of processing video and audio directly, which no longer requires conversion into anything, such as understanding subtle details in how a user speaks to reflect on their mood and emphasis. We can expect Grok 4.20 to use this V7 model, but the ambiguity remains.

There’s another major update that is pending from xAI, and it’s a larger video format for the Grok Imagine model, which should have exceeded 15 seconds or more, yet the company is running late on this front.