Google opens Gemini 4 Argon to paying users and developers

Who gets it: In the Gemini app, Argon is limited to AI Pro ($20 a month) and AI Ultra (from $99 a month) subscribers, Ars Technica reported. In Antigravity, Google's agent-based coding tool, and in AI Studio, it is available only on Ultra plans. Pro subscribers can still generate code with Argon in the app's Canvas mode, and Google is keeping Gemini 3.1 Pro available for now. The Verge said it is not clear when, or whether, free users will get the model.

What it costs developers: Introductory API pricing is $2 per million input tokens and $10 per million output tokens, with cached input 95% off. After Nov. 30 it rises to $4 and $20. The Verge estimated the introductory rate at about a fifth of the cost of OpenAI's GPT-6 Astra and Anthropic's Fable 5 models, though it noted that models can use different numbers of tokens for the same task. Google says the API allows a combined 1 million input and output tokens.

What Google claims: Google says Argon tops the Vals Index, which measures work in finance, coding, law and tax, and The Verge reported that Google claims it beats GPT-6 Astra, Claude Fable 5.1 and Claude Opus 5.5 on a range of benchmarks. Internally, Google says Argon raised agentic code submissions in Antigravity by more than 35% while cutting code rollbacks by nearly a third. Ars Technica reported that Argon found redundant emoji rendering in YouTube's comment system that, once removed, cut server load by 45%, and found bugs dating to 2018 in the drone physics simulator used by Alphabet's Wing.

Safety and access: Google says external biology red-teamers could unlock less than 1% of the risky sub-tasks it tests for, and that shortcut attempts on coding tests fell to 2%. It also says an automated monitor reads the agent's reasoning and actions to block unintended workarounds. Google is expanding its Fairwind program, which gives vetted cyber defenders Argon without cyber guardrails, to hundreds more partners. It is also offering 10,000 scientists six months of Antigravity's top usage tier for free, subject to selection.

Timeline: On Sept. 30, Google announced Argon and released it only to Fairwind cyber defenders. On Oct. 4, Bloomberg reported that some people with access doubted its real-world coding, which Google called inaccurate. On Oct. 12, Meta launched its own frontier models, Muse Wonder and Muse Wonder Full. On Oct. 13, Argon went live for paying users and developers.

What's still unknown: Independent benchmark results; whether the coding doubts Bloomberg reported hold up now that more people can test it; when, or whether, free users and lower-tier Antigravity plans get Argon, which Google declined to say, according to Ars Technica; and the rest of the Gemini 4 family, which Google says is still coming.

Updated Oct. 13, 2026, ~10:15 a.m. PT for the public launch; the Oct. 4 version covered the limited release and Bloomberg's report of internal doubts. Availability, prices, internal results and safety figures come from Google's Oct. 13 blog posts. Plan prices and the Antigravity limits come from Ars Technica. The comparison with OpenAI and Anthropic models is Google's claim, as The Verge reported, and The Verge's cost comparison is its own estimate; US Brief has not seen independent benchmark results. Ars Technica notes Google is citing the same benchmarks it published in late September.