Agent Arena Analysis Shows Gemini 4 Carbon Widens Cost Edge on Long Tasks
Arena.ai's Agent Arena analysis finds that Gemini 4 Carbon becomes increasingly cost-competitive as task complexity rises. On typical tasks, GPT-6 Astra costs about 3.4x and Claude Opus 5.5 about 3.9x as much as Carbon, while across the most expensive 5% of sessions Opus rises to 4.2x and Astra's cost roughly doubles relative to Carbon. The finding is relevant for budgeting long-horizon agent workloads.
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Arena.ai (@arena) · 2026-11-10 19
Our recent Agent Arena analysis found that Gemini 4 Carbon by @GoogleDeepMind becomes more cost-competitive as tasks get more demanding.
Its savings relative to GPT-6 Astra and Claude Opus 5.5 grow on the most expensive sessions.
↳ 引用 @arena (Arena.ai): Models by @GoogleDeepMind scale better on cost than their rivals.
Gemini 4 Carbon is the prime example. As tasks get more demanding, every rival gets more expensive relative to Carbon.
For a typical task, GPT-6 Astra by @OpenAI costs 3.4× as much, Claude Opus 5.5 by @AnthropicAI costs 3.9× as much, and GPT-6.1 Sol is the cheaper option at about half of Carbon’s cost (0.54×).
Across the 5% most expensive sessions, Carbon’s position improves against all three. Opus edges up to 4.2×, Astra’s cost roughly doubles relative to Carbon, and Sol’s discount shrinks.
This in turn can translate into meaningful savings across real-world tasks such as building an Android security app, one of many long-horizon tasks that our Agent Arena users delegate to their agents.