head-to-head

MetricClaude Opus 4.8GPT-5.5
SWE-bench Verified~86%82.6%
SWE-bench Pro69.2%58.6%
Terminal-Bench~82.7% (TB2.1)82.7% (TB2.0)
Input $ / 1M$5
Context1M
Open weightsNoNo
MakerAnthropicOpenAI

when to pick each

Pick Claude Opus 4.8 if

The hardest agentic refactors and long, autonomous multi-file tasks where every point of accuracy saves a human review cycle.

Pick GPT-5.5 if

OpenAI's strongest agentic coder, with the deepest tooling and ecosystem breadth of the closed labs.

Ranked on our AI Coding Leaderboard, updated 2026-07-02. Scores are confirmed against primary sources; prices are per 1M input tokens and can change.

Primary sources