# GPT-5.6 Luna vs Inkling

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

- Canonical page: https://benchlm.ai/compare/gpt-5-6-luna-vs-inkling
- Last updated: October 14, 2026

- Shared sourced benchmarks: 13
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Pick GPT-5.6 Luna if you want the stronger benchmark profile. Inkling 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 64.19 to 52.13.
- The clearest category separation is in coding, where the averages are 61.8 for GPT-5.6 Luna and 34 for Inkling.
- The biggest single benchmark swing is FrontierMath v2 (Tier 4) in Mathematics, with scores of 58.500% and 4.878%.
- 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 | GPT-5.6 Luna | Inkling |
|----------|----------|----------|
| Creator | OpenAI | Thinking Machines Lab |
| Type | Proprietary | Open Weight |
| Reasoning | Reasoning | Hybrid |
| Context | 1.05M | 1M |
| Overall Score | 64.19 | 52.13 |
| Benchmarks Covered | 31 | 24 |
| Pricing (input/output) | $0.20 / $1.20 | $1.87 / $4.68 |

## Category Breakdown

### Agentic

- Winner: GPT-5.6 Luna
- GPT-5.6 Luna public-lane score: 54.5 (Supported · #38/124)
- Inkling public-lane score: 36.2 (Supported · #72/124)

| Benchmark | GPT-5.6 Luna | Inkling | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 3.0 | 14.3% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | 84.7% | 63.8% | GPT-5.6 Luna |
| BrowseComp | 83.3% | 77.1% | GPT-5.6 Luna |
| 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% | 47.6% | GPT-5.6 Luna |
| ApprenticeBench | 7% | Coming soon | Coming soon |
| MCP Atlas | Coming soon | 74.1% | Coming soon |
| CWE-bench v1 | Coming soon | 37.0% | Coming soon |

### Coding

- Winner: GPT-5.6 Luna
- GPT-5.6 Luna public-lane score: 61.8 (Supported · #16/149)
- Inkling public-lane score: 34 (Supported · #80/149)

| Benchmark | GPT-5.6 Luna | Inkling | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Pro | 62.7% | 54.3% | GPT-5.6 Luna |
| Terminal-Bench 2.1 | 84.7% | 63.8% | GPT-5.6 Luna |
| DeepSWE | 67.2% | Coming soon | Coming soon |
| FrontierCode 1.1 Extended | 55.1% | Coming soon | Coming soon |
| CursorBench 3.2 | 61.1% | Coming soon | Coming soon |
| VulcanBench v3 | 85.5% | Coming soon | Coming soon |
| SWE-bench (Vals) | 93.0% | 77.6% | GPT-5.6 Luna |
| CursorBench 4.0 | 35.9% | Coming soon | Coming soon |
| SWE-bench Verified | Coming soon | 77.6% | Coming soon |
| FrontierSWE v2 | Coming soon | 4.1% | Coming soon |
| LiveCodeBench (Vals) | Coming soon | 85.5% | Coming soon |

### Reasoning

- Winner: Directional only
- GPT-5.6 Luna public-lane score: 58.2 (#28/29)
- Inkling public-lane score: 79 (#14/29)

| Benchmark | GPT-5.6 Luna | Inkling | Winner |
|-----------|-----------|-----------|--------|
| ARC-AGI-2 | 59.5% | Coming soon | Coming soon |
| ARC-AGI-3 | 0.2% | Coming soon | Coming soon |
| ARC-AGI-1 | 88.00% | Coming soon | Coming soon |

### Multimodal & Grounded

- Winner: Directional only
- GPT-5.6 Luna public-lane score: 79.6 (#19/54)
- Inkling public-lane score: 67.5 (#35/54)

| Benchmark | GPT-5.6 Luna | Inkling | Winner |
|-----------|-----------|-----------|--------|
| MMMU-Pro | 78.4% | 73.5% | GPT-5.6 Luna |
| MMMU-Pro w/ Python | 79.5% | Coming soon | Coming soon |
| CharXiv | Coming soon | 82% | Coming soon |
| CharXiv w/o tools | Coming soon | 78.1% | Coming soon |

### Knowledge

- Winner: GPT-5.6 Luna
- GPT-5.6 Luna public-lane score: 64.5 (Supported · #37/181)
- Inkling public-lane score: 54.5 (Supported · #62/181)

| Benchmark | GPT-5.6 Luna | Inkling | Winner |
|-----------|-----------|-----------|--------|
| GPQA | 92.3% | 87.9% | GPT-5.6 Luna |
| GPQA-D | 92.3% | 87.9% | 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% | 87.1% | GPT-5.6 Luna |
| MMLU-Pro (Vals) | 86.0% | 86.3% | Inkling |
| HLE | Coming soon | 46% | Coming soon |
| HLE w/o tools | Coming soon | 30% | Coming soon |

### Instruction Following

- Winner: Not comparable
- GPT-5.6 Luna public-lane score: Coming soon
- Inkling public-lane score: 87.6 (#35/128)

| Benchmark | GPT-5.6 Luna | Inkling | Winner |
|-----------|-----------|-----------|--------|
| IFBench | Coming soon | 79.8% | Coming soon |

### Mathematics

- Winner: Not comparable
- GPT-5.6 Luna public-lane score: 84 (Unranked · 3 rankable rows)
- Inkling public-lane score: 58.3 (#11/12)

| Benchmark | GPT-5.6 Luna | Inkling | Winner |
|-----------|-----------|-----------|--------|
| FrontierMath (legacy) | 78.6% | Coming soon | Coming soon |
| FrontierMath v2 (Tiers 1-3) | 78.600% | 33.333% | GPT-5.6 Luna |
| FrontierMath v2 (Tier 4) | 58.500% | 4.878% | GPT-5.6 Luna |
| AIME26 | Coming soon | 97.1% | Coming soon |

## FAQ

### Which is better overall, GPT-5.6 Luna or Inkling?

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

### Where is the biggest gap between GPT-5.6 Luna and Inkling?

The widest category gap is in coding, where the averages are 61.8 for GPT-5.6 Luna and 34 for Inkling.

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

GPT-5.6 Luna currently has 31 sourced benchmark scores on BenchLM.

### How many benchmarks does Inkling cover on BenchLM?

Inkling currently has 24 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)
- [Inkling vs GPT-5.6 Sol](/compare/gpt-5-6-sol-vs-inkling)
- [GPT-5.6 Luna vs GPT-5.6 Terra](/compare/gpt-5-6-luna-vs-gpt-5-6-terra)
- [Inkling vs GPT-5.6 Terra](/compare/gpt-5-6-terra-vs-inkling)

## Explore More

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