Google set to launch Gemini 4 Argon, testing stronger Carbon version

Google is about to officially release its new Gemini 4 "Argon" model to the public, while internal staff are already testing an even stronger follow-up version that could further close the gap with rivals.

According to internal documents and screenshots, Google employees have been testing a new version codenamed "Carbon". It has been integrated into Google's internal code platform Jetski and is likely a checkpoint update under the Argon architecture.

One employee said Carbon's coding skills are "comparable to Anthropic's Opus 5.5", though this still needs deeper testing. Early Argon versions got good reviews in internal tests, but they struggled with some coding tasks, performing roughly at the level of Anthropic's earlier Claude Opus 5.

Google's internal codenames often don't match public release names, so it's unclear whether Carbon will be a fine-tuned version or a standalone model. Google declined to comment.