# Gemini 3.5 Flash vs GPT-6 Astra

> GPT-6 Astra is the stronger model overall, scoring 70.8 to 54.2 on the Noometry Index. Gemini 3.5 Flash costs 5.9× less per token, which makes it the better buy when GPT-6 Astra's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/gemini-3-5-flash-vs-gpt-6-astra
- Last updated: 2026-10-10
- Shared benchmarks: 44

## Summary

- They share 44 benchmarks with published results for both. Gemini 3.5 Flash scores higher in 3 categories and GPT-6 Astra in 7 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in math, where GPT-6 Astra leads 93.5 to 60.7.
- The biggest single-benchmark swing is EBR-Bench: 4.8% for Gemini 3.5 Flash and 76.2% for GPT-6 Astra.
- Gemini 3.5 Flash is cheaper at $1.50 / $9 per million input/output tokens, against $10 / $50 for GPT-6 Astra.
- GPT-6 Astra accepts more context: 1.05M tokens versus 1.05M.

## Snapshot

| | Gemini 3.5 Flash | GPT-6 Astra |
|---|---|---|
| Provider | Google | OpenAI |
| Noometry Index | 54.2 | 70.8 |
| Rank | 32 | 1 |
| Context | 1.05M | 1.05M |
| Input $/M | $1.50 | $10 |
| Output $/M | $9 | $50 |
| Weights | Proprietary | Proprietary |

## Coding

- Gemini 3.5 Flash: 49.4 (#49)
- GPT-6 Astra: 73.7 (#2)

| Benchmark | Gemini 3.5 Flash | GPT-6 Astra |
|---|---|---|
| DeepSWE | 37.4% | 74.1% |
| LMArena WebDev | 1499 | 1786 |
| SciCode | 53.1% | 56.5% |
| WeirdML | 62.6% | 93.6% |
| LMArena Coding | 1492 | 1487 |
| ALE-Bench | 911.02 | 2,951 |
| SWE-bench Verified | 79.3% | — |
| FrontierCode | — | 53.3% |
| FrontierSWE | — | 65.5% |
| GSO | — | 79.4% |
| MirrorCode | — | 46.7% |

## Agentic & Tool Use

- Gemini 3.5 Flash: 24.7 (#114)
- GPT-6 Astra: 52.9 (#3)

| Benchmark | Gemini 3.5 Flash | GPT-6 Astra |
|---|---|---|
| APEX-Agents | 27.5% | 64.7% |
| GDP.pdf | 14% | 34.2% |
| Vending-Bench 2 | 5,396 | 15,515 |
| Remote Labor Index | — | 20.8% |
| BALROG | — | 68.3% |
| GBAEval | 6.7% | — |

## Reasoning

- Gemini 3.5 Flash: 62.8 (#18)
- GPT-6 Astra: 85.1 (#1)

| Benchmark | Gemini 3.5 Flash | GPT-6 Astra |
|---|---|---|
| ARC-AGI-2 | 72.1% | 95% |
| NYT Connections (extended) | 92.6% | 98.1% |
| ARC-AGI-1 | 92.5% | 98.5% |
| CritPt | 13.1% | 31.7% |
| Chess Puzzles | 50% | 72% |
| EBR-Bench | 4.8% | 76.2% |
| LMArena Hard Prompts | 1488 | 1462 |
| Mystery Game Puzzles | 32% | 84% |
| DTBench | 94.7% | 97.3% |
| LMCA | 47.1% | 64.4% |
| Epoch Capabilities Index | 154.46 | 166.45 |
| SimpleBench | 76.7% | — |
| EnigmaEval | 25.4% | — |
| Surface Evolver Bench | 58.1% | — |
| Bench to the Future 3 | — | 0.14 |
| ForecastBench | 59 | — |

## Math

- Gemini 3.5 Flash: 60.7 (#36)
- GPT-6 Astra: 93.5 (#2)

| Benchmark | Gemini 3.5 Flash | GPT-6 Astra |
|---|---|---|
| FrontierMath (Tiers 1-3) | 62.8% | 93.7% |
| FrontierMath Tier 4 | 26.8% | 97.6% |
| OTIS Mock AIME 2024-2025 | 95.6% | 100% |
| ProofBench | 31% | 99% |
| LMArena Math | 1504 | 1465 |
| MathArena Final-Answer Competitions | 76.3% | — |
| FrontierMath (Feb 2025 set) | 39% | — |
| FrontierMath Erdős | — | 2.9% |
| FrontierMath Tier 4 (v1) | 14.6% | — |

## Knowledge

- Gemini 3.5 Flash: 66.3 (#11)
- GPT-6 Astra: 75.3 (#1)

| Benchmark | Gemini 3.5 Flash | GPT-6 Astra |
|---|---|---|
| GPQA Diamond | 92.8% | 95.8% |
| SimpleQA Verified | 66.2% | 75.6% |
| LMArena Expert | 1495 | 1483 |
| Humanity's Last Exam | — | 54.8% |
| Vectara Hallucination Rate | — | 8.7% |

## Multimodal

- Gemini 3.5 Flash: 45.7 (#15)
- GPT-6 Astra: 55.0 (#3)

| Benchmark | Gemini 3.5 Flash | GPT-6 Astra |
|---|---|---|
| LMArena Vision | 1310 | 1281 |
| Blueprint-Bench 2 | 33.6% | 49.7% |
| LMArena Document | 1463 | 1468 |
| Furniture Assembly | — | 80% |

## Multilingual

- Gemini 3.5 Flash: 57.0 (#13)
- GPT-6 Astra: 53.7 (#61)

| Benchmark | Gemini 3.5 Flash | GPT-6 Astra |
|---|---|---|
| LMArena Non-English | 1476 | 1430 |
| LMArena Chinese | 1526 | 1484 |
| LMArena French | 1490 | 1456 |
| LMArena German | 1492 | 1440 |
| LMArena Japanese | 1486 | 1379 |
| LMArena Korean | 1451 | 1426 |
| LMArena Russian | 1493 | 1436 |
| LMArena Spanish | 1480 | 1407 |

## Instruction Following

- Gemini 3.5 Flash: 77.0 (#30)
- GPT-6 Astra: 76.3 (#44)

| Benchmark | Gemini 3.5 Flash | GPT-6 Astra |
|---|---|---|
| LMArena Instruction Following | 1467 | 1450 |

## Long Context

- Gemini 3.5 Flash: 45.4 (#38)
- GPT-6 Astra: 44.5 (#62)

| Benchmark | Gemini 3.5 Flash | GPT-6 Astra |
|---|---|---|
| LMArena Longer Query | 1482 | 1456 |

## Writing & Preference

- Gemini 3.5 Flash: 65.5 (#47)
- GPT-6 Astra: 75.3 (#7)

| Benchmark | Gemini 3.5 Flash | GPT-6 Astra |
|---|---|---|
| LMArena Text | 1482 | 1441 |
| LMArena Creative Writing | 1470 | 1418 |
| LMArena Multi-Turn | 1481 | 1448 |
| EQ-Bench Creative Writing | — | 2173 |
| EQ-Bench 4 | 1087 | — |

## FAQ

### Is Gemini 3.5 Flash better than GPT-6 Astra?

GPT-6 Astra is the stronger model overall, scoring 70.8 to 54.2 on the Noometry Index. Gemini 3.5 Flash costs 5.9× less per token, which makes it the better buy when GPT-6 Astra's lead doesn't matter for your workload.

### Which is cheaper, Gemini 3.5 Flash or GPT-6 Astra?

Gemini 3.5 Flash is cheaper. It lists at $1.50 per million input tokens and $9 per million output tokens; GPT-6 Astra lists at $10 and $50.

### Is Gemini 3.5 Flash or GPT-6 Astra better for coding?

GPT-6 Astra scores higher on coding benchmarks: 73.7 versus 49.4 in the Noometry coding category.

### Which has the bigger context window?

GPT-6 Astra does, with 1.05M tokens against 1.05M.

### How many benchmarks do Gemini 3.5 Flash and GPT-6 Astra share?

44 benchmarks have published results for both models. Gemini 3.5 Flash has 54 scored results on Noometry and GPT-6 Astra has 56.