Google has given employees access to a new, internally tested Gemini model codenamed Hydrogen, according to an internal message seen by Business Insider. A Google engineer described the model to staff as "very capable, fast and efficient."

Staff can try it in the company's internal development platform, known as Jetski, which Business Insider notes often pre-empts a public launch.

An employee who has used Hydrogen told Business Insider it feels akin to Google's previous Flash models, the workhorse tier built to be faster and more cost-effective than flagship models like Argon.

As the lightest element in the periodic table, Hydrogen would be a fitting name for the lightest Gemini 4 model.

The internal test is a sign of momentum for a company that many had written off earlier this year.

Business Insider reports that after Google delayed and then ultimately canceled Gemini 3.5 Pro, observers considered the company to have fallen behind in the race for the most advanced AI models, known as the frontier.

Google has since, in Business Insider's words, roared back to life with the Gemini 4 family. A speed-and-efficiency model in testing suggests Google is now filling out that lineup quickly, moving from frontier releases toward the faster, cheaper tiers that reach the broadest audience.

Hydrogen follows the release of Gemini 4 Argon and Carbon. On Tuesday, Google announced the rollout of Gemini 4 Carbon, which it says is strongest for cybersecurity and long-horizon, multi-step tasks, according to Business Insider.

SiliconANGLE reports that Google DeepMind used the same day to debut the next generation of Gemini Robotics and AlphaGenome 2, with Gemini Robotics 2.5 described as the company's most capable vision-language-action model to date, tested across more than 200 distinct tasks and built on capabilities behind the Gemini 4 Argon frontier model released in late September.

Competition is heating up too: Business Insider notes Anthropic announced new Fable and Mythos models on Monday, saying they are more capable at finding cybersecurity flaws and designing physical hardware.

It is not yet clear whether Hydrogen, if released, would be a paid or free offering, Business Insider reports. That distinction matters because both Argon and Carbon are currently limited to paying users, while Google offers its other Flash models for free in the Gemini app.

Business Insider also cautions that Jetski access frequently precedes a public launch, but an internal test is no guarantee of one. Google declined to comment on the record.

If Hydrogen follows the Flash playbook, a free, fast, low-cost tier could broaden Gemini's reach as Anthropic and other rivals press their own new model lines.