# Claude Sonnet 5 vs GPT-5.6 Luna

> Side-by-side benchmark comparison for Claude Sonnet 5 and GPT-5.6 Luna across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-sonnet-5-vs-gpt-5-6-luna
- Last updated: September 29, 2026

- Shared sourced benchmarks: 12
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.7

## Quick Verdict

Pick Claude Sonnet 5 if you want the stronger benchmark profile. GPT-5.6 Luna only makes more sense when its price, context window, or workload-specific category wins matter more than the overall score.

## Summary

- Claude Sonnet 5 leads overall 66.99 to 65.55.
- The clearest category separation is in reasoning, where the averages are 78.7 for Claude Sonnet 5 and 55.8 for GPT-5.6 Luna.
- The biggest single benchmark swing is SWE-bench (Vals) in Coding, with scores of 79.6% and 93.0%.
- GPT-5.6 Luna is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.
- GPT-5.6 Luna also has the larger context window at 1.05M.

## Model Snapshot

| Property | Claude Sonnet 5 | GPT-5.6 Luna |
|----------|----------|----------|
| Creator | Anthropic | OpenAI |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 1.05M |
| Overall Score | 66.99 | 65.55 |
| Benchmarks Covered | 26 | 30 |
| Pricing (input/output) | $2.00 / $10.00 | $0.20 / $1.20 |

## Category Breakdown

### Agentic

- Winner: Claude Sonnet 5
- Claude Sonnet 5 public-lane score: 64.6 (Supported · #12/117)
- GPT-5.6 Luna public-lane score: 55.2 (Supported · #33/117)

| Benchmark | Claude Sonnet 5 | GPT-5.6 Luna | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 3.0 | 14.6% | 14.3% | Claude Sonnet 5 |
| Terminal-Bench 2.1 | 80.4% | 84.7% | GPT-5.6 Luna |
| BrowseComp | 84.7% | 83.3% | Claude Sonnet 5 |
| HLE w/ tools | 57.4% | Coming soon | Coming soon |
| OSWorld-Verified | 81.2% | Coming soon | Coming soon |
| Terminal-Bench 2.1 (Vals) | 74.5% | 79.0% | GPT-5.6 Luna |
| ApprenticeBench | 16% | 7% | Claude Sonnet 5 |
| OSWorld 2.0 | Coming soon | 45.6% | Coming soon |
| CyberGym | Coming soon | 77.9% | Coming soon |
| ExploitGym | Coming soon | 12.4% | Coming soon |
| Toolathlon | Coming soon | 53.4% | Coming soon |

### Coding

- Winner: GPT-5.6 Luna
- Claude Sonnet 5 public-lane score: 59.8 (Supported · #19/142)
- GPT-5.6 Luna public-lane score: 63.2 (Supported · #11/142)

| Benchmark | Claude Sonnet 5 | GPT-5.6 Luna | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 85.2% | Coming soon | Coming soon |
| SWE-bench Pro | 63.2% | 62.7% | Claude Sonnet 5 |
| SWE Multilingual | 78.3% | Coming soon | Coming soon |
| SWE Multimodal | 28.1% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | 80.4% | 84.7% | GPT-5.6 Luna |
| FrontierCode 1.1 Main | 42.7% | Coming soon | Coming soon |
| cursorBench32 | 61.5% | 61.1% | Claude Sonnet 5 |
| VulcanBench CII v1 | 89.2% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 82.4% | Coming soon | Coming soon |
| SWE-bench (Vals) | 79.6% | 93.0% | GPT-5.6 Luna |
| cursorBench40 | 34.1% | 35.9% | GPT-5.6 Luna |
| DeepSWE | Coming soon | 67.2% | Coming soon |
| FrontierCode 1.1 Extended | Coming soon | 55.1% | Coming soon |
| VulcanBench v3 | Coming soon | 85.5% | Coming soon |

### Reasoning

- Winner: Not comparable
- Claude Sonnet 5 public-lane score: 78.7 (Unranked · 2 rankable rows)
- GPT-5.6 Luna public-lane score: 55.8 (#24/27)

| Benchmark | Claude Sonnet 5 | GPT-5.6 Luna | Winner |
|-----------|-----------|-----------|--------|
| ARC-AGI-2 | Coming soon | 59.5% | Coming soon |
| ARC-AGI-3 | Coming soon | 0.2% | Coming soon |

### Multimodal & Grounded

- Winner: Directional only
- Claude Sonnet 5 public-lane score: 78.4 (#15/50)
- GPT-5.6 Luna public-lane score: 68.1 (#22/50)

| Benchmark | Claude Sonnet 5 | GPT-5.6 Luna | Winner |
|-----------|-----------|-----------|--------|
| CharXiv | 88.3% | Coming soon | Coming soon |
| CharXiv w/o tools | 77% | Coming soon | Coming soon |
| MMMU-Pro | Coming soon | 78.4% | Coming soon |
| MMMU-Pro w/ Python | Coming soon | 79.5% | Coming soon |

### Knowledge

- Winner: Tie
- Claude Sonnet 5 public-lane score: 64.5 (Supported · #26/168)
- GPT-5.6 Luna public-lane score: 64.7 (Supported · #25/168)

| Benchmark | Claude Sonnet 5 | GPT-5.6 Luna | Winner |
|-----------|-----------|-----------|--------|
| HLE | 57.4% | Coming soon | Coming soon |
| HLE w/o tools | 43.2% | Coming soon | Coming soon |
| HLE-Verified | 31.0% | Coming soon | Coming soon |
| LABBench2 | 80.1% | Coming soon | Coming soon |
| GPQA Diamond (Vals) | 88.9% | 91.7% | GPT-5.6 Luna |
| MMLU-Pro (Vals) | 87.5% | 86.0% | Claude Sonnet 5 |
| GPQA | Coming soon | 92.3% | Coming soon |
| GPQA-D | Coming soon | 92.3% | Coming soon |
| HealthBench Professional | Coming soon | 55.7% | Coming soon |
| HealthBench Hard | Coming soon | 32.0% | Coming soon |

### Mathematics

- Winner: Not comparable
- Claude Sonnet 5 public-lane score: Coming soon
- GPT-5.6 Luna public-lane score: 94.2 (Unranked · 3 rankable rows)

| Benchmark | Claude Sonnet 5 | GPT-5.6 Luna | Winner |
|-----------|-----------|-----------|--------|
| FrontierMath (legacy) | Coming soon | 78.6% | Coming soon |
| FrontierMath v2 (Tiers 1-3) | Coming soon | 78.600% | Coming soon |
| FrontierMath v2 (Tier 4) | Coming soon | 58.500% | Coming soon |

## FAQ

### Which is better overall, Claude Sonnet 5 or GPT-5.6 Luna?

Claude Sonnet 5 is ahead overall on BenchLM right now.

### Where is the biggest gap between Claude Sonnet 5 and GPT-5.6 Luna?

The widest category gap is in reasoning, where the averages are 78.7 for Claude Sonnet 5 and 55.8 for GPT-5.6 Luna.

### How many benchmarks does Claude Sonnet 5 cover on BenchLM?

Claude Sonnet 5 currently has 26 sourced benchmark scores on BenchLM.

### How many benchmarks does GPT-5.6 Luna cover on BenchLM?

GPT-5.6 Luna currently has 30 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Claude Sonnet 5 vs GPT-5.6 Sol](/compare/claude-sonnet-5-vs-gpt-5-6-sol)
- [GPT-5.6 Luna vs GPT-5.6 Sol](/compare/gpt-5-6-luna-vs-gpt-5-6-sol)
- [Claude Sonnet 5 vs GPT-5.6 Terra](/compare/claude-sonnet-5-vs-gpt-5-6-terra)
- [GPT-5.6 Luna vs GPT-5.6 Terra](/compare/gpt-5-6-luna-vs-gpt-5-6-terra)

## Explore More

- [Claude Sonnet 5 profile](/models/claude-sonnet-5)
- [GPT-5.6 Luna profile](/models/gpt-5-6-luna)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)