Claude Opus 5vsGPT-5.5-Pro
Claude Opus 5 | GPT-5.5-Pro | |
|---|---|---|
| Specifications | ||
Context window | 1M | — |
| 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 DeepSWE 1.1Artificial Analysis' independent test of deep, agentic software-engineering work — the AI has to plan and carry out substantial coding tasks end to end. (Version 1.1 of the test.) Higher is better. | 68.8% | — |
Agentic coding FrontierCode v1.1 (Main)A set of very hard, frontier-difficulty coding tasks an AI agent has to complete end to end. The score is the share of tasks in the main split it solves. Higher is better. | 53.4% | — |
Next.js coding Next.js EvalsVercel's open eval of how well AI coding agents build and migrate real Next.js apps — measured as the share of tasks the agent completes successfully. Higher is better. | — | 83% |
Agentic computer work Frontier-Bench v0.1A hard, ever-evolving set of real computer tasks — coding, system administration, data work, and more — that an AI agent has to complete on its own. Run by the Harbor / Laude Institute team as the successor to Terminal-Bench (v0.1 is the first release of the task set). The score is the share of tasks solved. Higher is better. | 43.3% | — |
Web browsing BrowseCompCan the AI browse the web and track down hard-to-find answers? Higher is better. | 90.8%Best | 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. | 56.3% | — |
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. | 64.7%Best | 57.2% |
Novel problem-solving ARC-AGI-3The third generation of the ARC-AGI series: instead of static puzzles, the AI is dropped into small interactive game-like environments it has never seen and has to figure out the rules and solve them on its own. Higher is better. | 30.2% | — |
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% |
Biology BioMysteryBench · hardReal unsolved-style biology puzzles — the AI has to reason its way to an answer the way a research biologist would. The “hard” split contains the toughest cases. Higher is better. | 49.4% | — |
Biology BioMysteryBench · human solvedReal biology puzzles that human experts have managed to crack — can the AI reach the same answers? Higher is better. | 90.1% | — |
Agentic computer use OSWorld 2.0Can the AI actually operate a computer — clicking, typing, and using real apps — to finish tasks on its own? Version 2.0 is a harder, refreshed task set. Higher is better. | 70.6% | — |
Business workflows AutomationBenchTests whether the AI can run real multi-step business workflows — the kind of end-to-end office processes companies want to automate — from start to finish. Higher is better. | 26% | — |
Agentic legal work Harvey's Legal Agent Benchmark (Held-out)Harvey's test of whether an AI agent can complete real legal work, scored on a held-out set of tasks the model makers never see — making the numbers harder to game. Higher is better. | 11.7% | — |
Health HealthBench ProfessionalRealistic health conversations graded against detailed rubrics written by physicians — can the AI respond the way a careful medical professional would? Higher is better. | 59.8% | — |
Knowledge work GDPval-AA v2economically valuable knowledge work (v2, re-based Elo) | 1861 | — |
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% |
| Overview | ||
| Company | Anthropic | OpenAI |
| Release date | Jul 24 2026 | Apr 23 2026 |
| Access | Proprietary | Proprietary |
Which is better: Claude Opus 5 or GPT-5.5-Pro?
Claude Opus 5 leads GPT-5.5-Pro on 2 of the 2 benchmarks they both report (BrowseComp, Humanity's Last Exam). GPT-5.5-Pro shipped 92 days before Claude Opus 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.
On BrowseComp, Claude Opus 5 leads at 90.8% vs GPT-5.5-Pro at 90.1%. On Humanity's Last Exam · with tools, Claude Opus 5 leads at 64.7% vs GPT-5.5-Pro at 57.2%.
Frequently asked questions
Claude Opus 5 was released by Anthropic on Jul 24 2026.
GPT-5.5-Pro was released by OpenAI on Apr 23 2026.
Claude Opus 5 leads on Humanity's Last Exam · with tools — Claude Opus 5 64.7% vs GPT-5.5-Pro 57.2%.
Other comparisons
Claude Opus 5vsGemini 3.6 FlashGPT-5.5-ProvsGemini 3.6 FlashClaude Opus 5vsMuse Spark 1.1GPT-5.5-ProvsMuse Spark 1.1Claude Opus 5vsGrok 4.5GPT-5.5-ProvsGrok 4.5Claude Opus 5vsDeepSeek-V4-ProGPT-5.5-ProvsDeepSeek-V4-ProClaude Opus 5vsMistral Medium 3.5GPT-5.5-ProvsMistral Medium 3.5Claude Opus 5vsKimi K3GPT-5.5-ProvsKimi K3