Anthropic's Claude Sonnet 5 Takes No.6 on Code Arena Frontend, Up 29 Points on Predecessor

The thinking version of Claude Sonnet 5, released by Anthropic on June 30, 2026, has ranked No.6 (score 1551) on Code Arena: Frontend, which evaluates agentic frontend web development. It topped its predecessor Sonnet 4.6 (No.13, 1522) by +29 points and even edged out the higher-tier Opus 4.6 (Thinking) by +9 points. The Arena.ai leaderboard uses ELO ratings from more than 420,000 anonymous head-to-head votes and is closely watched as a real-world comparison of models on frontend web development tasks.