GPT-5.5 dominates benchmarks as Claude Sonnet 4.6 wins on price
OpenAI's GPT-5.5 wins 10 of 13 benchmarks but costs nearly double.
In the latest head-to-head comparison between two leading AI models, GPT-5.5 from OpenAI significantly outperforms Claude Sonnet 4.6 from Anthropic across most standard benchmarks, winning 10 out of 13 shared evaluations. GPT-5.5 excels in demanding tests like ARC-AGI v2, BrowseComp, GPQA, Humanity's Last Exam, LiveBench, MCP Atlas, MMMU-Pro, Tau2 Telecom, and Terminal-Bench 2.0, while Claude Sonnet 4.6 only leads in three: Finance Agent (original), GDPval-AA, and Legal Agent Benchmark. This makes GPT-5.5 the clear choice for tasks requiring top-tier reasoning, browsing, and agentic performance.
On pricing, Claude Sonnet 4.6 is roughly 1.9x cheaper per token on a blended 3:1 input/output basis — $3/$15 per million tokens vs GPT-5.5's $5/$30. This cost advantage adds up rapidly at production scale. However, GPT-5.5 compensates with a massive 1,050,000 input token context window (vs 200k) and can generate up to 128,000 output tokens (vs 64k). Released two months later (April 2026 vs February 2026), GPT-5.5 also benefits from more recent training data through December 2025. Both models support multimodal inputs (text, images, audio, video) and are proprietary. The verdict: choose Claude Sonnet 4.6 if budget is your primary constraint, but choose GPT-5.5 for raw capability, long-context tasks, and the latest knowledge.
- GPT-5.5 wins 10 out of 13 benchmarks vs Claude Sonnet 4.6's 3 wins
- Claude Sonnet 4.6 is 1.9x cheaper per token ($3/$15 vs $5/$30 per million)
- GPT-5.5 has a 1,050,000 token context window vs Claude's 200,000 and supports up to 128,000 output tokens
Why It Matters
Professionals must choose between cutting-edge capability at higher cost or budget-friendly performance for production workloads.