Arena says GPT-6 Astra led Code Arena: WebDev on September 12

In its September 12, 2026 update, Arena put OpenAI’s GPT-6 Astra first at 1,796 points, followed by Claude Fable 5.1 at 1,764 and Alibaba’s Qwen at 1,685. Arena says the leading score rose by 340 points over the preceding year. It describes Anthropic as dominant throughout that period, while noting that Kimi K3 reached the top spot in July.