# GPT-5.6 Luna vs Qwen3.8-27B

> Side-by-side benchmark comparison for GPT-5.6 Luna and Qwen3.8-27B across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/gpt-5-6-luna-vs-qwen3-8-27b
- Last updated: September 28, 2026

- Shared sourced benchmarks: 11
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.7

## Quick Verdict

Pick GPT-5.6 Luna if you want the stronger benchmark profile. Qwen3.8-27B only makes more sense when its price, context window, or workload-specific category wins matter more than the overall score.

## Summary

- GPT-5.6 Luna leads overall 65.55 to 55.26.
- The clearest category separation is in reasoning, where the averages are 55.8 for GPT-5.6 Luna and 78.7 for Qwen3.8-27B.
- The biggest single benchmark swing is DeepSWE in Coding, with scores of 67.2% and 42.2%.
- Qwen3.8-27B 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 | GPT-5.6 Luna | Qwen3.8-27B |
|----------|----------|----------|
| Creator | OpenAI | Alibaba |
| Type | Proprietary | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 1.05M | 262K |
| Overall Score | 65.55 | 55.26 |
| Benchmarks Covered | 30 | 33 |
| Pricing (input/output) | $0.20 / $1.20 | $0.00 / $0.00 |

## Category Breakdown

### Agentic

- Winner: Qwen3.8-27B
- GPT-5.6 Luna public-lane score: 55.2 (Supported · #33/117)
- Qwen3.8-27B public-lane score: 61.2 (Supported · #18/117)

| Benchmark | GPT-5.6 Luna | Qwen3.8-27B | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 3.0 | 14.3% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | 84.7% | 73.0% | GPT-5.6 Luna |
| BrowseComp | 83.3% | Coming soon | Coming soon |
| OSWorld 2.0 | 45.6% | Coming soon | Coming soon |
| CyberGym | 77.9% | Coming soon | Coming soon |
| ExploitGym | 12.4% | Coming soon | Coming soon |
| Toolathlon | 53.4% | Coming soon | Coming soon |
| Terminal-Bench 2.1 (Vals) | 79.0% | 58.4% | GPT-5.6 Luna |
| ApprenticeBench | 7% | Coming soon | Coming soon |
| CoWorkBench | Coming soon | 70.7% | Coming soon |
| JobBench | Coming soon | 33.4% | Coming soon |
| Agents' Last Exam | Coming soon | 42.9% | Coming soon |
| OSWorld-Verified | Coming soon | 84.3% | Coming soon |
| WebArena-Verified | Coming soon | 64.8% | Coming soon |
| AndroidWorld | Coming soon | 81.9% | Coming soon |

### Coding

- Winner: GPT-5.6 Luna
- GPT-5.6 Luna public-lane score: 63.1 (Supported · #11/142)
- Qwen3.8-27B public-lane score: 48.7 (Supported · #45/142)

| Benchmark | GPT-5.6 Luna | Qwen3.8-27B | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Pro | 62.7% | 61.7% | GPT-5.6 Luna |
| Terminal-Bench 2.1 | 84.7% | 73.0% | GPT-5.6 Luna |
| DeepSWE | 67.2% | 42.2% | GPT-5.6 Luna |
| FrontierCode 1.1 Extended | 55.1% | Coming soon | Coming soon |
| cursorBench32 | 61.1% | Coming soon | Coming soon |
| VulcanBench v3 | 85.5% | 82.6% | GPT-5.6 Luna |
| SWE-bench (Vals) | 93.0% | 86.0% | GPT-5.6 Luna |
| cursorBench40 | 35.9% | Coming soon | Coming soon |
| NL2Repo | Coming soon | 42.3% | Coming soon |
| LiveCodeBench v6 | Coming soon | 90.3% | Coming soon |
| LiveCodeBench (Vals) | Coming soon | 84.0% | Coming soon |

### Reasoning

- Winner: Directional only
- GPT-5.6 Luna public-lane score: 55.8 (#24/27)
- Qwen3.8-27B public-lane score: 78.7 (#8/27)

| Benchmark | GPT-5.6 Luna | Qwen3.8-27B | Winner |
|-----------|-----------|-----------|--------|
| ARC-AGI-2 | 59.5% | Coming soon | Coming soon |
| ARC-AGI-3 | 0.2% | Coming soon | Coming soon |

### Multimodal & Grounded

- Winner: Directional only
- GPT-5.6 Luna public-lane score: 68.1 (#22/50)
- Qwen3.8-27B public-lane score: 80.9 (#11/50)

| Benchmark | GPT-5.6 Luna | Qwen3.8-27B | Winner |
|-----------|-----------|-----------|--------|
| MMMU-Pro | 78.4% | Coming soon | Coming soon |
| MMMU-Pro w/ Python | 79.5% | Coming soon | Coming soon |
| MathVision | Coming soon | 90.0% | Coming soon |
| MathVision w/ Python | Coming soon | 94.6% | Coming soon |
| BabyVision | Coming soon | 65.7% | Coming soon |
| BabyVision w/ Python | Coming soon | 85.6% | Coming soon |
| Vision2Web | Coming soon | 62.9% | Coming soon |
| CharXiv w/o tools | Coming soon | 83.7% | Coming soon |
| CharXiv | Coming soon | 90.2% | Coming soon |
| OmniDocBench 1.5 | Coming soon | 91.1% | Coming soon |
| RealWorldQA | Coming soon | 85.9% | Coming soon |
| ERQA | Coming soon | 65.5% | Coming soon |

### Knowledge

- Winner: GPT-5.6 Luna
- GPT-5.6 Luna public-lane score: 64.7 (Supported · #25/168)
- Qwen3.8-27B public-lane score: 49.2 (Supported · #63/168)

| Benchmark | GPT-5.6 Luna | Qwen3.8-27B | Winner |
|-----------|-----------|-----------|--------|
| GPQA | 92.3% | 89.2% | GPT-5.6 Luna |
| GPQA-D | 92.3% | 89.2% | GPT-5.6 Luna |
| HealthBench Professional | 55.7% | Coming soon | Coming soon |
| HealthBench Hard | 32.0% | Coming soon | Coming soon |
| GPQA Diamond (Vals) | 91.7% | 88.9% | GPT-5.6 Luna |
| MMLU-Pro (Vals) | 86.0% | 84.3% | GPT-5.6 Luna |
| HLE | Coming soon | 30.8% | Coming soon |
| HLE w/o tools | Coming soon | 30.8% | Coming soon |

### Instruction Following

- Winner: Not comparable
- GPT-5.6 Luna public-lane score: Coming soon
- Qwen3.8-27B public-lane score: 83.2 (#45/124)

| Benchmark | GPT-5.6 Luna | Qwen3.8-27B | Winner |
|-----------|-----------|-----------|--------|
| IFBench | Coming soon | 79.5% | Coming soon |

### Mathematics

- Winner: Not comparable
- GPT-5.6 Luna public-lane score: 94.2 (Unranked · 3 rankable rows)
- Qwen3.8-27B public-lane score: Coming soon

| Benchmark | GPT-5.6 Luna | Qwen3.8-27B | Winner |
|-----------|-----------|-----------|--------|
| FrontierMath (legacy) | 78.6% | Coming soon | Coming soon |
| FrontierMath v2 (Tiers 1-3) | 78.600% | Coming soon | Coming soon |
| FrontierMath v2 (Tier 4) | 58.500% | Coming soon | Coming soon |

## FAQ

### Which is better overall, GPT-5.6 Luna or Qwen3.8-27B?

GPT-5.6 Luna is ahead overall on BenchLM right now.

### Where is the biggest gap between GPT-5.6 Luna and Qwen3.8-27B?

The widest category gap is in reasoning, where the averages are 55.8 for GPT-5.6 Luna and 78.7 for Qwen3.8-27B.

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

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

### How many benchmarks does Qwen3.8-27B cover on BenchLM?

Qwen3.8-27B currently has 33 sourced benchmark scores on BenchLM.

## Related Comparisons

- [GPT-5.6 Luna vs GPT-5.6 Sol](/compare/gpt-5-6-luna-vs-gpt-5-6-sol)
- [Qwen3.8-27B vs GPT-5.6 Sol](/compare/gpt-5-6-sol-vs-qwen3-8-27b)
- [GPT-5.6 Luna vs GPT-5.6 Terra](/compare/gpt-5-6-luna-vs-gpt-5-6-terra)
- [Qwen3.8-27B vs GPT-5.6 Terra](/compare/gpt-5-6-terra-vs-qwen3-8-27b)

## Explore More

- [GPT-5.6 Luna profile](/models/gpt-5-6-luna)
- [Qwen3.8-27B profile](/models/qwen3-8-27b)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)