Google’s Gemini 4 Carbon ranked first in the Artificial Analysis Intelligence Index released Wednesday, scoring 59 points and narrowly edging Anthropic’s Claude Opus 5.5 and OpenAI’s GPT-6 Astra. The model is not available to ordinary paying users: Google is initially making it available through its Fairwind program to vetted cybersecurity defenders and has not said when developers, businesses or consumers will get access. Alphabet shares rose about 1.5% on the day the results were announced.
Carbon leads the index by one point
The Artificial Analysis Intelligence Index is an independent ranking of AI models. Gemini 4 Carbon scored 59, compared with 58 for Claude Opus 5.5 and 57 for GPT-6 Astra. The close results put Carbon at the top of this particular composite evaluation, but do not establish that it performs better across every use case.
Google also highlighted Carbon’s results on cybersecurity testing. The company said the model scored 54.8% on ExploitGym, a test that assesses whether a model can verify that software vulnerabilities can be exploited in practice. GPT-6 Astra scored 42.4%, while Claude Opus 5.5 scored 34.5%. Those figures relate to a specific test and do not measure the models’ overall capabilities or performance in real-world settings.
Initial access restricted to cybersecurity defenders
Google says Carbon will first be available to cybersecurity defenders vetted through its Fairwind program. Developers, businesses and consumers may receive access later, but the company has not announced a date. The staged rollout keeps the model’s initial reach limited; paying customers cannot simply purchase or call it through an API at this point.
Google has linked the phased access to its security arrangements, citing Carbon’s results on tests related to hacking. The company disabled safety filters during external cybersecurity testing. Google is also taking part in voluntary US government testing of models before release. It has not disclosed specific requirements for broader access or a timetable for expanding availability.
Google used a phased rollout for Argon
Google’s previous top model, Gemini 4 Argon, followed a similar release path. It became available to paying developers on October 13. Google has not said whether Carbon will follow the same schedule or when it might reach that stage.
For Alphabet, Carbon’s ranking adds a new set of performance results to its competition in AI products. But access remains restricted, and customers’ ability to use the model will depend on rollout plans Google has yet to announce. The information currently available covers the model’s scores, its cybersecurity test results and the first group of users; it does not establish how quickly commercial access will expand.