# Gemini 3.6 Flash vs GPT-5.6 Luna

> Side-by-side benchmark comparison for Gemini 3.6 Flash and GPT-5.6 Luna across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/gemini-3-6-flash-vs-gpt-5-6-luna
- Last updated: September 4, 2026

- Shared sourced benchmarks: 6
- HTML indexing: indexable
- Ranking lane: BenchAlign v5

## Quick Verdict

Pick Gemini 3.6 Flash 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

- Gemini 3.6 Flash leads overall 70.11 to 65.54.
- The clearest category separation is in reasoning, where the averages are 77.8 for Gemini 3.6 Flash and 50.4 for GPT-5.6 Luna.
- The biggest single benchmark swing is deepSwe in Coding, with scores of 49% and 67.2%.
- 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 | Gemini 3.6 Flash | GPT-5.6 Luna |
|----------|----------|----------|
| Creator | Google | OpenAI |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 1.05M |
| Overall Score | 70.11 | 65.54 |
| Benchmarks Covered | 8 | 28 |
| Pricing (input/output) | $1.50 / $7.50 | $1.00 / $6.00 |

## Category Breakdown

### Agentic

- Winner: GPT-5.6 Luna
- Gemini 3.6 Flash public-lane score: 50.7 (Supported · #60/151)
- GPT-5.6 Luna public-lane score: 56.5 (Supported · #34/151)

| Benchmark | Gemini 3.6 Flash | GPT-5.6 Luna | Winner |
|-----------|-----------|-----------|--------|
| OSWorld-Verified | 83% | Coming soon | Coming soon |
| Terminal-Bench 2.1 (Vals) | 73.8% | 79.0% | GPT-5.6 Luna |
| Terminal-Bench 3.0 | Coming soon | 14.3% | Coming soon |
| Terminal-Bench 2.0 | Coming soon | 84.7% | Coming soon |
| BrowseComp | Coming soon | 83.3% | Coming soon |
| 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
- Gemini 3.6 Flash public-lane score: 58.9 (Supported · #30/183)
- GPT-5.6 Luna public-lane score: 67 (Supported · #10/183)

| Benchmark | Gemini 3.6 Flash | GPT-5.6 Luna | Winner |
|-----------|-----------|-----------|--------|
| deepSwe | 49% | 67.2% | GPT-5.6 Luna |
| cursorBench32 | 53.5% | 61.1% | GPT-5.6 Luna |
| LiveCodeBench (Vals) | 88.1% | Coming soon | Coming soon |
| SWE-bench (Vals) | 79.6% | 93.0% | GPT-5.6 Luna |
| SWE-bench Pro | Coming soon | 62.7% | Coming soon |
| Terminal-Bench 2.0 | Coming soon | 84.7% | Coming soon |
| FrontierCode 1.1 Extended | Coming soon | 55.1% | Coming soon |
| VulcanBench v3 | Coming soon | 85.5% | Coming soon |

### Multimodal & Grounded

- Winner: Coming soon
- Gemini 3.6 Flash public-lane score: 82.3 (Unranked · 1 rankable row)
- GPT-5.6 Luna public-lane score: 66.3 (#21/48)

| Benchmark | Gemini 3.6 Flash | GPT-5.6 Luna | Winner |
|-----------|-----------|-----------|--------|
| MMMU-Pro | Coming soon | 78.4% | Coming soon |
| MMMU-Pro w/ Python | Coming soon | 79.5% | Coming soon |

### Reasoning

- Winner: Coming soon
- Gemini 3.6 Flash public-lane score: 77.8 (Unranked · 2 rankable rows)
- GPT-5.6 Luna public-lane score: 50.4 (#21/22)

| Benchmark | Gemini 3.6 Flash | GPT-5.6 Luna | Winner |
|-----------|-----------|-----------|--------|
| ARC-AGI-2 | Coming soon | 59.5% | Coming soon |
| ARC-AGI-3 | Coming soon | 0.2% | Coming soon |

### Knowledge

- Winner: Gemini 3.6 Flash
- Gemini 3.6 Flash public-lane score: 68.6 (Supported · #18/181)
- GPT-5.6 Luna public-lane score: 64.7 (Supported · #27/181)

| Benchmark | Gemini 3.6 Flash | GPT-5.6 Luna | Winner |
|-----------|-----------|-----------|--------|
| GPQA Diamond (Vals) | 93.4% | 91.7% | Gemini 3.6 Flash |
| MMLU-Pro (Vals) | 89.3% | 86.0% | Gemini 3.6 Flash |
| 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: Coming soon
- Gemini 3.6 Flash public-lane score: Coming soon
- GPT-5.6 Luna public-lane score: 94.4 (Unranked · 3 rankable rows)

| Benchmark | Gemini 3.6 Flash | 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, Gemini 3.6 Flash or GPT-5.6 Luna?

Gemini 3.6 Flash is ahead overall on BenchLM right now.

### Where is the biggest gap between Gemini 3.6 Flash and GPT-5.6 Luna?

The widest category gap is in reasoning, where the averages are 77.8 for Gemini 3.6 Flash and 50.4 for GPT-5.6 Luna.

### How many benchmarks does Gemini 3.6 Flash cover on BenchLM?

Gemini 3.6 Flash currently has 8 sourced benchmark scores on BenchLM.

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

GPT-5.6 Luna currently has 28 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Gemini 3.6 Flash vs GPT-5.6 Sol](/compare/gemini-3-6-flash-vs-gpt-5-6-sol)
- [GPT-5.6 Luna vs GPT-5.6 Sol](/compare/gpt-5-6-luna-vs-gpt-5-6-sol)
- [Gemini 3.6 Flash vs GPT-5.6 Terra](/compare/gemini-3-6-flash-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

- [Gemini 3.6 Flash profile](/models/gemini-3-6-flash)
- [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)