Gemini 4 Carbon: who can use it and what it costs
Gemini 4 Carbon lists $2 per million input tokens at its introductory API rate, rising to $4 later. Here is who gets it first and how it compares to Argon.
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Can you use Gemini 4 Carbon yet?How much does Gemini 4 Carbon cost?How does Carbon compare to Gemini 4 Argon?What Google says Gemini 4 Carbon scoresWhat Gemini 4 Carbon means for youGemini 4 Carbon is Google's newest model, and most people can't use it yet: Google is giving it to a group of cyber defenders first, then to trusted partners in its Fairwind Program. Google announced it on October 28, 2026, at an introductory API price of $2 per million input tokens and $10 per million output tokens, the same as Gemini 4 Argon.
Can you use Gemini 4 Carbon yet?
Most people can't. Google's Carbon announcement of October 28, 2026 says the model goes first to a subset of cyber defenders, then to trusted partners through the Fairwind Program. Developers, businesses and consumers come next. Google says that will happen "via our product surfaces as soon as possible" and gives no date.
Google also says Carbon is taking part in the U.S. government's voluntary pre-release model testing process.
How much does Gemini 4 Carbon cost?
Gemini 4 Carbon costs $2 per million input tokens and $10 per million output tokens at its introductory API rate, according to a footnote in Google's October 28 announcement. Cached input tokens cost 95% less than the input price. After the introductory period, the footnote lists $4 per million input tokens and $20 per million output tokens.
The Carbon announcement does not say when the introductory period ends. Argon's does have a date. On October 31, 2026, the Gemini Developer API pricing page listed gemini-4-argon at $2.00 input and $10.00 output through November 30, 2026. From December 1, 2026 the page lists $4.00 and $20.00. Context caching for Argon goes from $0.10 to $0.20 on the same date.
Google Carbon announcement and Gemini Developer API pricing page, read October 31, 2026
If you plan to build on either model, budget for the higher rate from the start.
How does Carbon compare to Gemini 4 Argon?
Google announced Gemini 4 Argon on September 30, 2026 and Carbon on October 28, 2026. The token prices match. The changes Google claims are mostly in security and in how often the model overreaches. All of the figures below come from Google's own testing:
- Generating secure code: more than twice Argon's success rate on internal benchmarks.
- CWE-bench patching: Carbon scores 71.0% on CWE-bench (Collinear). Argon's announcement gave a 68% top score on CWE-bench v1, a tie for first. The two posts name the benchmark differently, so the versions may not match.
- Prompt injection: on the Gray Swan Indirect Prompt Injection benchmark, Carbon's attack success rate is 0.0%. Google gives Argon's as 0.7%.
- Unsupported claims: cut by approximately 2x compared with Argon, in internal testing.
Argon still has numbers Google has not published for Carbon. Argon scored 77.9% on DeepSWE v1.1, and its output limit rose to 1M tokens from 64K. The Carbon announcement gives neither figure.
What Google says Gemini 4 Carbon scores
Google's October 28 announcement puts Gemini 4 Carbon at #1 on the Artificial Analysis Intelligence Index v5.0, with a score of 59. Its security results are SEC-bench Pro 88.2% and ExploitGym 54.8%.
On WebDev Arena, Google lists Carbon at 1768 elo, rank #4, and writes that "Carbon jumps +89 elo points."
Google also reports changes in behavior from its own tests:
- On Terminal-Bench 4.0, successful cheating fell to 0.0%, and the model attempted to cheat 0.4% of the time.
- High-severity misalignment alerts in live internal coding dropped by almost 80%.
- Overreach fell 26% and under-service fell 29%.
What Gemini 4 Carbon means for you
For now, Gemini 4 Carbon is in the hands of cyber defenders and Fairwind Program partners. Everyone else waits for Google to open it to developers and consumers. When it opens, the introductory price will match what Argon costs today, and you should expect $4 and $20 per million tokens once the introductory period ends.
Every benchmark here is Google's own figure. If secure code or fewer made-up claims matter for your work, try both models on the same tasks once you have access. Then decide.
How we checked: on October 31, 2026 we read Google's Gemini 4 Carbon announcement of October 28, its Gemini 4 Argon announcement of September 30, and the Gemini Developer API pricing page. We did not rerun any benchmark. For another recent launch explained in plain words, see our posts on OpenAI's Terra launch and Kimi K3.1 Pro pricing.
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