Claude Sonnet 5 vs GPT-5.5-Pro
Anthropic Claude Sonnet 5 | OpenAI GPT-5.5-Pro | |
|---|---|---|
| Overview | ||
| Company | Anthropic | OpenAI |
| Release date | Jun 30 2026 | Apr 23 2026 |
| Access | Proprietary | Proprietary |
| Benchmarks | ||
Nonsense detection BullshitBench v2Given a confidently-worded but nonsensical prompt, does the AI spot that it makes no sense and push back — instead of playing along and inventing an answer? The score is how often it clearly called out the nonsense. Higher is better. | — | 36% |
Agentic coding SWE-Bench ProCan the AI fix real bugs in real software? It's handed actual problems from open-source projects and has to write code that genuinely solves them. Higher is better. | 63.2% | — |
Agentic coding CursorBench v3.1Cursor's own test of harder, real-world coding tasks inside a code editor. Higher is better. | 61.2% | — |
Agentic terminal coding Terminal-Bench 2.1Can the AI work in a command-line terminal — running commands and finishing technical setup tasks the way a developer would? Higher is better. | 80.4% | — |
Web browsing BrowseCompCan the AI browse the web and track down hard-to-find answers? Higher is better. | — | 90.1% |
Multidisciplinary reasoning Humanity's Last Exam · no toolsHumanity's Last Exam — extremely hard expert questions across many subjects, written so you can't just look up the answer. “No tools” means the AI answers on its own. Higher is better. | 43.2% | — |
Multidisciplinary reasoning Humanity's Last Exam · with toolsHumanity's Last Exam — extremely hard expert questions across many subjects. “With tools” means the AI is allowed to search the web or run code while answering. Higher is better. | 57.4% | — |
Advanced math FrontierMath · Tier 1–3Very hard, research-level math problems. Tiers 1–3 are the (still extremely difficult) lower tiers. Higher is better. | — | 52.4% |
Advanced math FrontierMath · Tier 4Very hard, research-level math problems. Tier 4 is the hardest — close to what professional research mathematicians tackle. Higher is better. | — | 39.6% |
Agentic computer use OSWorld-VerifiedCan the AI actually operate a computer — clicking, typing, and using real apps — to finish tasks on its own? Higher is better. | 81.2% | — |
Knowledge work GDPval-AAMeasures how well the AI does economically valuable knowledge work, judged against human experts. Shown as a rating (like a chess Elo) — higher is better. | 1618 | — |
Knowledge work GDPval (win/tie rate)How often the AI's work matches or beats a human expert's on real knowledge-work tasks. Higher is better. | — | 82.3% |
| Timeline | ||
| Release gap | GPT-5.5-Pro shipped 68 days before Claude Sonnet 5 | |
Which is better: Claude Sonnet 5 or GPT-5.5-Pro?
Claude Sonnet 5 and GPT-5.5-Pro don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. GPT-5.5-Pro shipped 68 days before Claude Sonnet 5, so benchmark comparisons should account for the intervening progress.
Published specifications for these two models are limited — see each model page for the latest details.
Direct benchmark comparisons are unavailable — Claude Sonnet 5 and GPT-5.5-Pro don't publish scores on any of the same benchmarks.
Frequently asked questions
Claude Sonnet 5 was released by Anthropic on Jun 30 2026.
GPT-5.5-Pro was released by OpenAI on Apr 23 2026.
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