Gemini 4 Carbon Now Available: Who Can Use It, Pricing

On November 10, 2026, Google opened Gemini 4 Carbon, its most capable model, to paying developers, businesses and Google AI Ultra subscribers. Until now only a group of cyber defenders could use it. It costs $2 per million input tokens and $10 per million output tokens until November 30; after that, twice as much.

What we know

What it is: Google calls it its strongest model, with frontier performance in cybersecurity and long-running agent work: multi-step coding, full-stack web development, debugging and research.
It doesn't replace Argon: the announcement says Gemini 4 Argon "remains the ideal choice" for most software engineering and knowledge work. Carbon joins the family.
It uses more tokens: according to Google, Carbon spends more tokens than Argon to explore, reason and verify its own work.
Who has it today: paying developers through the API in Google AI Studio and Android Studio; businesses through Gemini for business; and Google AI Ultra subscribers in the Gemini app, AI Mode in Search and Google Antigravity. Scientists can apply for 6 months of free access, subject to selection.
Price: the same introductory price as Argon, $2 per million input tokens and $10 per million output tokens. A footnote in the announcement says that once the introductory period ends on November 30, 2026, $4 and $20 will apply.
Performance: Google says Carbon ranks first on agent benchmarks such as CursorBench 4.0 and Zapier AutomationBench, at more than 2x lower cost per task than the next external model. These are Google's and its partners' numbers; there is no broad independent measurement yet.

What changes and what doesn't

Access changes. On October 30, Carbon was limited to a group of cyber defenders. Now any paid API account can use it.
There is no general free tier. The announcement covers the paid tier; the only free route is for selected scientists.
Argon's price goes up too. The Gemini API pricing page lists Gemini 4 Argon at $2 and $10 through November 30 and $4 and $20 from December 1. If your site already uses Argon, your bill changes in December even if you change nothing.
It isn't in the free app. In the Gemini app and AI Mode, Carbon is only for Google AI Ultra subscribers.

How to tell if it affects you

Check which model your site calls. If your chatbot, smart form or product-description generator uses the Gemini API, look in your code or your provider's dashboard for the configured model.
Run the December numbers. A task with 30,000 input tokens and 8,000 output tokens costs about $0.14 at the introductory price and about $0.28 from December, on Argon or Carbon. That is $140 versus $280 per 1,000 tasks. This is this article's estimate: reasoning is billed as output.
Count real tokens. Because Carbon reasons more, the same task can use much more output than on Argon. If a response uses twice the output tokens, that task costs almost twice as much even at the same per-token price.
Save Carbon for hard jobs. It fits security reviews of your site's code, large migrations or many-step agent tasks. For answering customer questions, summarizing or classifying, Google itself recommends Argon.
Test before November 30. The introductory price gives you a few weeks to compare both models on 20 or 30 real cases from your site and decide which tasks are worth the extra spend.

Sources

Updates: if Google adds Carbon's row to its API pricing page, changes the dates or opens it to more plans, it will be added here with its link.