Gemini 4 Carbon vs Argon: What Google says has improved and why access to the newer model starts differently

Argon launched through Google’s developer and enterprise channels and eligible consumer subscriptions on October 13. Carbon’s October 28 announcement starts with selected cyber defenders and trusted partners through Fairwind. Wider access is planned, so the newer name does not mean the same availability.

Google says Carbon achieved more than twice Argon’s success rate at generating secure code on internal benchmarks. That is a task specific result reported by the developer. It should not be rewritten as a claim that Carbon is twice as capable at everything.

Argon was already presented as a model for complex engineering and research. With Carbon, Google describes internal runs lasting days while the model works through difficult software problems. The emphasis is on sustained tasks such as tracing faults and developing patches across large codebases.

Google reports an attack success rate of 0.7% for Argon on the Gray Swan indirect prompt injection benchmark, falling to 0.0% for Carbon in its reported evaluation. Those figures describe that test; they do not establish protection against every possible malicious instruction.

Google announced Carbon at the same introductory API rates as Argon: $2 per million input tokens and $10 per million output tokens. These are usage prices, not monthly app subscriptions. Google’s pricing notes list higher standard rates after the introductory period.