# Claude Sonnet 5 vs GPT-5.5 Pro

> Side-by-side benchmark comparison for Claude Sonnet 5 and GPT-5.5 Pro across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-sonnet-5-vs-gpt-5-5-pro
- Last updated: September 29, 2026

- Shared sourced benchmarks: 3
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.7

## Quick Verdict

Evidence is too thin for a benchmark verdict: Claude Sonnet 5 and GPT-5.5 Pro share only 3 sourced benchmark rows.

## Summary

- Only 3 shared sourced benchmark rows are available. That is not enough for a broad capability verdict, so this mirror does not name an overall winner.
- Claude Sonnet 5 has the lower published output-token price.

## Model Snapshot

| Property | Claude Sonnet 5 | GPT-5.5 Pro |
|----------|----------|----------|
| Creator | Anthropic | OpenAI |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 1M |
| Independent public score (not head-to-head) | 66.72 | 72.18 |
| Benchmarks Covered | 26 | 8 |
| Pricing (input/output) | $2.00 / $10.00 | $30.00 / $180.00 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- Claude Sonnet 5 public-lane score: 64.6 (Supported · #13/117)
- GPT-5.5 Pro public-lane score: Coming soon

| Benchmark | Claude Sonnet 5 | GPT-5.5 Pro | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 3.0 | 14.6% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | 80.4% | Coming soon | Coming soon |
| BrowseComp | 84.7% | 90.1% | GPT-5.5 Pro |
| HLE w/ tools | 57.4% | Coming soon | Coming soon |
| OSWorld-Verified | 81.2% | Coming soon | Coming soon |
| Terminal-Bench 2.1 (Vals) | 74.5% | Coming soon | Coming soon |
| ApprenticeBench | 16% | Coming soon | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- Claude Sonnet 5 public-lane score: 60 (Supported · #20/143)
- GPT-5.5 Pro public-lane score: Coming soon

| Benchmark | Claude Sonnet 5 | GPT-5.5 Pro | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 85.2% | Coming soon | Coming soon |
| SWE-bench Pro | 63.2% | Coming soon | Coming soon |
| SWE Multilingual | 78.3% | Coming soon | Coming soon |
| SWE Multimodal | 28.1% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | 80.4% | Coming soon | Coming soon |
| FrontierCode 1.1 Main | 42.7% | Coming soon | Coming soon |
| cursorBench32 | 61.5% | Coming soon | Coming soon |
| VulcanBench CII v1 | 89.2% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 82.4% | Coming soon | Coming soon |
| SWE-bench (Vals) | 79.6% | Coming soon | Coming soon |
| cursorBench40 | 34.1% | Coming soon | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- Claude Sonnet 5 public-lane score: 78.7 (Unranked · 2 rankable rows)
- GPT-5.5 Pro public-lane score: 75.1 (Unranked · 3 rankable rows)

| Benchmark | Claude Sonnet 5 | GPT-5.5 Pro | Winner |
|-----------|-----------|-----------|--------|
| ARC-AGI-1 | Coming soon | 95.00% | Coming soon |
| ARC-AGI-2 | Coming soon | 84.2% | Coming soon |

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- Claude Sonnet 5 public-lane score: 78.4 (#15/50)
- GPT-5.5 Pro public-lane score: Coming soon

| Benchmark | Claude Sonnet 5 | GPT-5.5 Pro | Winner |
|-----------|-----------|-----------|--------|
| CharXiv | 88.3% | Coming soon | Coming soon |
| CharXiv w/o tools | 77% | Coming soon | Coming soon |

### Knowledge

- Winner: Insufficient shared evidence
- Claude Sonnet 5 public-lane score: 64.2 (Supported · #27/169)
- GPT-5.5 Pro public-lane score: Coming soon

| Benchmark | Claude Sonnet 5 | GPT-5.5 Pro | Winner |
|-----------|-----------|-----------|--------|
| HLE | 57.4% | 57.2% | Claude Sonnet 5 |
| HLE w/o tools | 43.2% | 43.1% | Claude Sonnet 5 |
| HLE-Verified | 31.0% | Coming soon | Coming soon |
| LABBench2 | 80.1% | Coming soon | Coming soon |
| GPQA Diamond (Vals) | 88.9% | Coming soon | Coming soon |
| MMLU-Pro (Vals) | 87.5% | Coming soon | Coming soon |

### Mathematics

- Winner: Insufficient shared evidence
- Claude Sonnet 5 public-lane score: Coming soon
- GPT-5.5 Pro public-lane score: 70.1 (Unranked · 3 rankable rows)

| Benchmark | Claude Sonnet 5 | GPT-5.5 Pro | Winner |
|-----------|-----------|-----------|--------|
| FrontierMath (legacy) | Coming soon | 52.4% | Coming soon |
| FrontierMath v2 (Tiers 1-3) | Coming soon | 51.000% | Coming soon |
| FrontierMath v2 (Tier 4) | Coming soon | 39.600% | Coming soon |

## FAQ

### Is there enough evidence to pick between Claude Sonnet 5 and GPT-5.5 Pro?

Not yet. The models share only 3 sourced benchmark rows, so this mirror reports the available measurements and metadata without naming a broad winner.

### What can I compare safely on this page?

Published pricing, context windows, model type, and individual shared benchmark rows are directly comparable. Independent overall scores and non-overlapping benchmark coverage are labeled separately and should not be read as a controlled head-to-head result.

## Related Comparisons

- [Claude Sonnet 5 vs GPT-5.5](/compare/claude-sonnet-5-vs-gpt-5-5)
- [GPT-5.5 Pro vs GPT-5.5](/compare/gpt-5-5-vs-gpt-5-5-pro)
- [Claude Sonnet 5 vs GPT-6 Astra](/compare/claude-sonnet-5-vs-gpt-6-astra)
- [GPT-5.5 Pro vs GPT-6 Astra](/compare/gpt-5-5-pro-vs-gpt-6-astra)

## Explore More

- [Claude Sonnet 5 profile](/models/claude-sonnet-5)
- [GPT-5.5 Pro profile](/models/gpt-5-5-pro)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)