# Gemini 3.5 Flash vs o3

> Gemini 3.5 Flash is the stronger model overall, scoring 54.2 to 47.5 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gemini-3-5-flash-vs-o3
- Last updated: 2026-10-10
- Shared benchmarks: 38

## Summary

- They share 38 benchmarks with published results for both. Gemini 3.5 Flash scores higher in 8 categories and o3 in 2 categories; 10 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Gemini 3.5 Flash leads 62.8 to 32.0.
- The biggest single-benchmark swing is ARC-AGI-2: 72.1% for Gemini 3.5 Flash and 6.5% for o3.
- Both cost about the same: $1.50 input and $9 output per million tokens.
- Gemini 3.5 Flash accepts more context: 1.05M tokens versus 200K.

## Snapshot

| | Gemini 3.5 Flash | o3 |
|---|---|---|
| Provider | Google | OpenAI |
| Noometry Index | 54.2 | 47.5 |
| Rank | 32 | 61 |
| Context | 1.05M | 200K |
| Input $/M | $1.50 | $2 |
| Output $/M | $9 | $8 |
| Weights | Proprietary | Proprietary |

## Coding

- Gemini 3.5 Flash: 49.4 (#49)
- o3: 46.8 (#64)

| Benchmark | Gemini 3.5 Flash | o3 |
|---|---|---|
| SWE-bench Verified | 79.3% | 62.3% |
| WeirdML | 62.6% | 52.4% |
| LMArena Coding | 1492 | 1408 |
| ALE-Bench | 911.02 | 933.55 |
| DeepSWE | 37.4% | — |
| SWE-bench Verified (bash only) | — | 58.4% |
| Aider Polyglot | — | 81.3% |
| LMArena WebDev | 1499 | — |
| SciCode | 53.1% | — |
| GSO | — | 8.8% |
| CadEval | — | 74% |

## Agentic & Tool Use

- Gemini 3.5 Flash: 24.7 (#114)
- o3: 34.5 (#44)

| Benchmark | Gemini 3.5 Flash | o3 |
|---|---|---|
| APEX-Agents | 27.5% | — |
| Berkeley Function Calling Leaderboard | — | 63% |
| GDPval | — | 30.8% |
| DeepResearch Bench | — | 45.2% |
| OSWorld | — | 23% |
| GBAEval | 6.7% | — |
| GDP.pdf | 14% | — |
| LMArena Search | — | 1144 |
| METR Time Horizons | — | 65.4% |
| Vending-Bench 2 | 5,396 | — |

## Reasoning

- Gemini 3.5 Flash: 62.8 (#18)
- o3: 32.0 (#78)

| Benchmark | Gemini 3.5 Flash | o3 |
|---|---|---|
| ARC-AGI-2 | 72.1% | 6.5% |
| SimpleBench | 76.7% | 53.1% |
| ARC-AGI-1 | 92.5% | 60.8% |
| CritPt | 13.1% | 1.4% |
| Chess Puzzles | 50% | 38% |
| EnigmaEval | 25.4% | 13.1% |
| LMArena Hard Prompts | 1488 | 1402 |
| Mystery Game Puzzles | 32% | 29% |
| DTBench | 94.7% | 84.8% |
| LMCA | 47.1% | 39.7% |
| Epoch Capabilities Index | 154.46 | 146.86 |
| ForecastBench | 59 | 62.5 |
| Kagi LLM Benchmark | — | 67.6% |
| NYT Connections (extended) | 92.6% | — |
| EBR-Bench | 4.8% | — |
| Surface Evolver Bench | 58.1% | — |

## Math

- Gemini 3.5 Flash: 60.7 (#36)
- o3: 50.2 (#58)

| Benchmark | Gemini 3.5 Flash | o3 |
|---|---|---|
| FrontierMath (Tiers 1-3) | 62.8% | 33.3% |
| OTIS Mock AIME 2024-2025 | 95.6% | 84.4% |
| LMArena Math | 1504 | 1426 |
| FrontierMath (Feb 2025 set) | 39% | 18.7% |
| FrontierMath Tier 4 (v1) | 14.6% | 2.1% |
| FrontierMath Tier 4 | 26.8% | — |
| MathArena Final-Answer Competitions | 76.3% | — |
| ProofBench | 31% | — |
| Omni-MATH | — | 71.4% |
| MATH Level 5 | — | 97.8% |

## Knowledge

- Gemini 3.5 Flash: 66.3 (#11)
- o3: 54.6 (#52)

| Benchmark | Gemini 3.5 Flash | o3 |
|---|---|---|
| GPQA Diamond | 92.8% | 81.8% |
| SimpleQA Verified | 66.2% | 49.4% |
| LMArena Expert | 1495 | 1402 |
| Humanity's Last Exam | — | 20.3% |
| MMLU-Pro | — | 85.9% |
| Confabulations | — | 14.4% |
| GPQA (HELM) | — | 75.3% |

## Multimodal

- Gemini 3.5 Flash: 45.7 (#15)
- o3: 41.4 (#36)

| Benchmark | Gemini 3.5 Flash | o3 |
|---|---|---|
| LMArena Vision | 1310 | 1214 |
| GeoBench | — | 74% |
| VPCT | — | 52% |
| Blueprint-Bench 2 | 33.6% | — |
| LMArena Document | 1463 | — |

## Multilingual

- Gemini 3.5 Flash: 57.0 (#13)
- o3: 51.7 (#105)

| Benchmark | Gemini 3.5 Flash | o3 |
|---|---|---|
| LMArena Non-English | 1476 | 1401 |
| LMArena Chinese | 1526 | 1437 |
| LMArena French | 1490 | 1430 |
| LMArena German | 1492 | 1420 |
| LMArena Japanese | 1486 | 1403 |
| LMArena Korean | 1451 | 1370 |
| LMArena Russian | 1493 | 1406 |
| LMArena Spanish | 1480 | 1395 |

## Instruction Following

- Gemini 3.5 Flash: 77.0 (#30)
- o3: 72.8 (#127)

| Benchmark | Gemini 3.5 Flash | o3 |
|---|---|---|
| LMArena Instruction Following | 1467 | 1368 |
| IFEval | — | 86.9% |

## Long Context

- Gemini 3.5 Flash: 45.4 (#38)
- o3: 53.3 (#6)

| Benchmark | Gemini 3.5 Flash | o3 |
|---|---|---|
| LMArena Longer Query | 1482 | 1372 |
| Fiction.LiveBench | — | 88.9% |
| CL-bench | — | 17.8% |

## Writing & Preference

- Gemini 3.5 Flash: 65.5 (#47)
- o3: 63.5 (#64)

| Benchmark | Gemini 3.5 Flash | o3 |
|---|---|---|
| LMArena Text | 1482 | 1410 |
| LMArena Creative Writing | 1470 | 1359 |
| LMArena Multi-Turn | 1481 | 1405 |
| Short-Story Creative Writing | — | 83.9% |
| EQ-Bench Creative Writing | — | 1676 |
| WildBench | — | 86.1% |
| EQ-Bench 4 | 1087 | — |

## FAQ

### Is Gemini 3.5 Flash better than o3?

Gemini 3.5 Flash is the stronger model overall, scoring 54.2 to 47.5 on the Noometry Index.

### Which is cheaper, Gemini 3.5 Flash or o3?

Gemini 3.5 Flash is cheaper. It lists at $1.50 per million input tokens and $9 per million output tokens; o3 lists at $2 and $8.

### Is Gemini 3.5 Flash or o3 better for coding?

Gemini 3.5 Flash scores higher on coding benchmarks: 49.4 versus 46.8 in the Noometry coding category.

### Which has the bigger context window?

Gemini 3.5 Flash does, with 1.05M tokens against 200K.

### How many benchmarks do Gemini 3.5 Flash and o3 share?

38 benchmarks have published results for both models. Gemini 3.5 Flash has 54 scored results on Noometry and o3 has 63.