# Claude Opus 4.5 vs GPT-5.5

> Side-by-side benchmark comparison for Claude Opus 4.5 and GPT-5.5 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-opus-4-5-vs-gpt-5-5
- Last updated: September 4, 2026

- Shared sourced benchmarks: 13
- HTML indexing: indexable
- Ranking lane: BenchAlign v5

## Quick Verdict

Pick GPT-5.5 if you want the stronger benchmark profile. Claude Opus 4.5 only makes more sense when its price, context window, or workload-specific category wins matter more than the overall score.

## Summary

- GPT-5.5 leads overall 73.27 to 60.24.
- The clearest category separation is in instruction following, where the averages are 39.5 for Claude Opus 4.5 and 92.9 for GPT-5.5.
- The biggest single benchmark swing is MCP Atlas in Agentic, with scores of 42.3% and 75.3%.
- Claude Opus 4.5 is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.
- GPT-5.5 also has the larger context window at 1M.

## Model Snapshot

| Property | Claude Opus 4.5 | GPT-5.5 |
|----------|----------|----------|
| Creator | Anthropic | OpenAI |
| Type | Proprietary | Proprietary |
| Reasoning | Non-Reasoning | Reasoning |
| Context | 200K | 1M |
| Overall Score | 60.24 | 73.27 |
| Benchmarks Covered | 45 | 38 |
| Pricing (input/output) | $5.00 / $25.00 | $5.00 / $30.00 |

## Category Breakdown

### Agentic

- Winner: Coming soon
- Claude Opus 4.5 public-lane score: 44.4 (Estimated · #101/151)
- GPT-5.5 public-lane score: 63.9 (Supported · #15/151)

| Benchmark | Claude Opus 4.5 | GPT-5.5 | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.0 | 59.3% | 82% | GPT-5.5 |
| OSWorld-Verified | 66.3% | 78.7% | GPT-5.5 |
| OSWorld | 66.3% | Coming soon | Coming soon |
| Claw-Eval | 59.6% | Coming soon | Coming soon |
| QwenClawBench | 52.3% | Coming soon | Coming soon |
| τ³-bench results | 70.2% | Coming soon | Coming soon |
| VITA-Bench | 23.3% | Coming soon | Coming soon |
| DeepPlanning | 26.4% | Coming soon | Coming soon |
| Toolathlon | 43.5% | 55.6% | GPT-5.5 |
| MCP Atlas | 42.3% | 75.3% | GPT-5.5 |
| MCP-Tasks | 71.8% | Coming soon | Coming soon |
| WideResearch | 76.4% | Coming soon | Coming soon |
| CyberGym | 50.6% | 81.8% | GPT-5.5 |
| Gert Labs | 64.23% | 72.93% | GPT-5.5 |
| JobBench | 32.3% | 42.7% | GPT-5.5 |
| BrowseComp | Coming soon | 84.4% | Coming soon |
| τ²-bench results | Coming soon | 98% | Coming soon |
| ResearchClawBench | Coming soon | 17.0% | Coming soon |
| OSWorld 2.0 | Coming soon | 13.0% | Coming soon |
| ExploitGym | Coming soon | 13.4% | Coming soon |
| Terminal-Bench 2.1 (Vals) | Coming soon | 76.4% | Coming soon |

### Coding

- Winner: GPT-5.5
- Claude Opus 4.5 public-lane score: 55.1 (Supported · #42/183)
- GPT-5.5 public-lane score: 67.7 (Supported · #8/183)

| Benchmark | Claude Opus 4.5 | GPT-5.5 | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 80.9% | Coming soon | Coming soon |
| LiveCodeBench v6 | 84.8% | Coming soon | Coming soon |
| SWE-bench Pro | 57.1% | 58.6% | GPT-5.5 |
| SWE Multilingual | 77.5% | Coming soon | Coming soon |
| NL2Repo | 43.2% | Coming soon | Coming soon |
| Terminal-Bench 2.0 | Coming soon | 82.0% | Coming soon |
| Vibe Code Bench | Coming soon | 69.85% | Coming soon |
| React Native Evals | Coming soon | 84.7% | Coming soon |
| cursorBench31 | Coming soon | 59.2% | Coming soon |
| cursorBench32 | Coming soon | 58.4% | Coming soon |
| FrontierCode 1.1 Main | Coming soon | 43.0% | Coming soon |
| LiveCodeBench (Vals) | Coming soon | 85.3% | Coming soon |
| SWE-bench (Vals) | Coming soon | 82.6% | Coming soon |

### Multimodal & Grounded

- Winner: Coming soon
- Claude Opus 4.5 public-lane score: 23.5 (#46/48)
- GPT-5.5 public-lane score: 71.3 (#19/48)

| Benchmark | Claude Opus 4.5 | GPT-5.5 | Winner |
|-----------|-----------|-----------|--------|
| MMMU-Pro | 70.6% | 81.2% | GPT-5.5 |
| MathVision | 74.3% | Coming soon | Coming soon |
| CharXiv | 68.5% | Coming soon | Coming soon |
| VideoMMMU | 84.4% | Coming soon | Coming soon |
| ScreenSpot Pro | 45.7% | Coming soon | Coming soon |
| V* | 67.0% | Coming soon | Coming soon |
| MMMU-Pro w/ Python | Coming soon | 83.2% | Coming soon |
| OfficeQA Pro | Coming soon | 54.1% | Coming soon |

### Reasoning

- Winner: Coming soon
- Claude Opus 4.5 public-lane score: 72.1 (Unranked · 4 rankable rows)
- GPT-5.5 public-lane score: 63.5 (#15/22)

| Benchmark | Claude Opus 4.5 | GPT-5.5 | Winner |
|-----------|-----------|-----------|--------|
| LongBench v2 | 64.4% | Coming soon | Coming soon |
| AI-Needle | 74% | Coming soon | Coming soon |
| MRCR v2 64K-128K | Coming soon | 83.1% | Coming soon |
| MRCR v2 128K-256K | Coming soon | 87.5% | Coming soon |
| ARC-AGI-2 | Coming soon | 85% | Coming soon |
| ARC-AGI-3 | Coming soon | 0.4% | Coming soon |

### Knowledge

- Winner: Coming soon
- Claude Opus 4.5 public-lane score: 55.4 (Estimated · #60/181)
- GPT-5.5 public-lane score: 73.3 (Supported · #7/181)

| Benchmark | Claude Opus 4.5 | GPT-5.5 | Winner |
|-----------|-----------|-----------|--------|
| GPQA | 87% | 93.6% | GPT-5.5 |
| SuperGPQA | 70.6% | Coming soon | Coming soon |
| MMLU-Pro | 89.5% | Coming soon | Coming soon |
| MMLU-Redux | 96.6% | Coming soon | Coming soon |
| C-Eval | 92.2% | Coming soon | Coming soon |
| HLE | 30.8% | 52.2% | GPT-5.5 |
| GPQA-D | Coming soon | 93.6% | Coming soon |
| HLE w/o tools | Coming soon | 41.4% | Coming soon |
| GPQA Diamond (Vals) | Coming soon | 93.2% | Coming soon |
| MMLU-Pro (Vals) | Coming soon | 88.1% | Coming soon |

### Instruction Following

- Winner: Coming soon
- Claude Opus 4.5 public-lane score: 39.5 (#103/120)
- GPT-5.5 public-lane score: 92.9 (#7/120)

| Benchmark | Claude Opus 4.5 | GPT-5.5 | Winner |
|-----------|-----------|-----------|--------|
| IFEval | 90.9% | Coming soon | Coming soon |
| IFBench | 58% | Coming soon | Coming soon |

### Multilingual

- Winner: Coming soon
- Claude Opus 4.5 public-lane score: 82.9 (#2/12)
- GPT-5.5 public-lane score: Coming soon

| Benchmark | Claude Opus 4.5 | GPT-5.5 | Winner |
|-----------|-----------|-----------|--------|
| MMLU-ProX | 85.7% | Coming soon | Coming soon |
| NOVA-63 | 56.7% | Coming soon | Coming soon |

### Mathematics

- Winner: Coming soon
- Claude Opus 4.5 public-lane score: 58.3 (#6/7)
- GPT-5.5 public-lane score: 69.6 (Unranked · 3 rankable rows)

| Benchmark | Claude Opus 4.5 | GPT-5.5 | Winner |
|-----------|-----------|-----------|--------|
| AIME26 | 95.1% | Coming soon | Coming soon |
| HMMT Feb 2025 | 92.9% | Coming soon | Coming soon |
| HMMT Nov 2025 | 93.3% | Coming soon | Coming soon |
| HMMT Feb 2026 | 85.3% | Coming soon | Coming soon |
| MMAnswerBench | 84.0% | Coming soon | Coming soon |
| FrontierMath v2 (Tiers 1-3) | 20.690% | 51.700% | GPT-5.5 |
| FrontierMath v2 (Tier 4) | 4.167% | 35.400% | GPT-5.5 |
| FrontierMath (legacy) | Coming soon | 51.7% | Coming soon |

## FAQ

### Which is better overall, Claude Opus 4.5 or GPT-5.5?

GPT-5.5 is ahead overall on BenchLM right now.

### Where is the biggest gap between Claude Opus 4.5 and GPT-5.5?

The widest category gap is in instruction following, where the averages are 39.5 for Claude Opus 4.5 and 92.9 for GPT-5.5.

### How many benchmarks does Claude Opus 4.5 cover on BenchLM?

Claude Opus 4.5 currently has 45 sourced benchmark scores on BenchLM.

### How many benchmarks does GPT-5.5 cover on BenchLM?

GPT-5.5 currently has 38 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Claude Opus 4.5 vs Claude Opus 4.5 Thinking](/compare/claude-opus-4-5-vs-claude-opus-4-5-thinking)
- [GPT-5.5 vs Claude Opus 4.5 Thinking](/compare/claude-opus-4-5-thinking-vs-gpt-5-5)
- [Claude Opus 4.5 vs GPT-5.5 Pro](/compare/claude-opus-4-5-vs-gpt-5-5-pro)
- [GPT-5.5 vs GPT-5.5 Pro](/compare/gpt-5-5-vs-gpt-5-5-pro)

## Explore More

- [Claude Opus 4.5 profile](/models/claude-opus-4-5)
- [GPT-5.5 profile](/models/gpt-5-5)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)