# Gemini 3.8 Flash vs GPT-5.5 Instant

> Gemini 3.8 Flash is the stronger model overall, scoring 61.8 to 42.7 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gemini-3-8-flash-vs-gpt-5-5-instant
- Last updated: 2026-10-12
- Shared benchmarks: 26

## Summary

- They share 26 benchmarks with published results for both. Gemini 3.8 Flash scores higher in 9 categories and GPT-5.5 Instant in 0 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Gemini 3.8 Flash leads 76.9 to 24.9.
- The biggest single-benchmark swing is Chess Puzzles: 61% for Gemini 3.8 Flash and 12% for GPT-5.5 Instant.

## Snapshot

| | Gemini 3.8 Flash | GPT-5.5 Instant |
|---|---|---|
| Provider | Google | OpenAI |
| Noometry Index | 61.8 | 42.7 |
| Rank | 11 | 110 |
| Context | 1.05M | — |
| Input $/M | $0.75 | — |
| Output $/M | $3.75 | — |
| Weights | Proprietary | Proprietary |

## Coding

- Gemini 3.8 Flash: 59.2 (#15)
- GPT-5.5 Instant: 44.3 (#74)

| Benchmark | Gemini 3.8 Flash | GPT-5.5 Instant |
|---|---|---|
| SciCode | 56.6% | 48.6% |
| LMArena Coding | 1510 | 1433 |
| DeepSWE | 73.8% | — |
| FrontierCode | 41.2% | — |
| CursorBench | 39.6% | — |
| LMArena WebDev | 1584 | — |
| FrontierSWE | 19.6% | — |
| WeirdML | 84.8% | — |
| ALE-Bench | 1,270 | — |

## Agentic & Tool Use

- Gemini 3.8 Flash: 41.8 (#21)
- GPT-5.5 Instant: —

| Benchmark | Gemini 3.8 Flash | GPT-5.5 Instant |
|---|---|---|
| APEX-Agents | 64.3% | — |
| Remote Labor Index | 5.8% | — |
| GDP.pdf | 23.4% | — |
| Vending-Bench 2 | 5,094 | — |

## Reasoning

- Gemini 3.8 Flash: 76.9 (#5)
- GPT-5.5 Instant: 24.9 (#155)

| Benchmark | Gemini 3.8 Flash | GPT-5.5 Instant |
|---|---|---|
| CritPt | 18.3% | 0% |
| Chess Puzzles | 61% | 12% |
| LMArena Hard Prompts | 1508 | 1426 |
| Epoch Capabilities Index | 156.71 | 142.52 |
| ARC-AGI-2 | 89.2% | — |
| NYT Connections (extended) | 97.4% | — |
| ARC-AGI-1 | 98.5% | — |
| Mystery Game Puzzles | 47% | — |
| DTBench | 95.7% | — |
| LMCA | 52.9% | — |
| Surface Evolver Bench | 76.9% | — |

## Math

- Gemini 3.8 Flash: 65.3 (#28)
- GPT-5.5 Instant: 26.5 (#259)

| Benchmark | Gemini 3.8 Flash | GPT-5.5 Instant |
|---|---|---|
| FrontierMath (Tiers 1-3) | 68.4% | 26.3% |
| FrontierMath Tier 4 | 22% | 2.4% |
| OTIS Mock AIME 2024-2025 | 98.9% | 68.1% |
| LMArena Math | 1528 | 1420 |
| ProofBench | 48% | — |

## Knowledge

- Gemini 3.8 Flash: 74.8 (#2)
- GPT-5.5 Instant: 48.9 (#74)

| Benchmark | Gemini 3.8 Flash | GPT-5.5 Instant |
|---|---|---|
| GPQA Diamond | 95.4% | 82.5% |
| LMArena Expert | 1524 | 1409 |
| Humanity's Last Exam | 44.5% | — |
| SimpleQA Verified | 69.7% | — |

## Multimodal

- Gemini 3.8 Flash: 40.7 (#45)
- GPT-5.5 Instant: 40.0 (#52)

| Benchmark | Gemini 3.8 Flash | GPT-5.5 Instant |
|---|---|---|
| LMArena Vision | 1314 | 1250 |
| Blueprint-Bench 2 | 38.6% | — |
| Furniture Assembly | 31.7% | — |
| LMArena Document | — | 1403 |

## Multilingual

- Gemini 3.8 Flash: 58.0 (#5)
- GPT-5.5 Instant: 52.8 (#80)

| Benchmark | Gemini 3.8 Flash | GPT-5.5 Instant |
|---|---|---|
| LMArena Non-English | 1491 | 1417 |
| LMArena Chinese | 1554 | 1456 |
| LMArena French | 1498 | 1428 |
| LMArena German | 1493 | 1411 |
| LMArena Japanese | 1502 | 1408 |
| LMArena Korean | 1459 | 1392 |
| LMArena Russian | 1515 | 1431 |
| LMArena Spanish | 1485 | 1429 |

## Instruction Following

- Gemini 3.8 Flash: 78.0 (#13)
- GPT-5.5 Instant: 74.2 (#100)

| Benchmark | Gemini 3.8 Flash | GPT-5.5 Instant |
|---|---|---|
| LMArena Instruction Following | 1490 | 1406 |

## Long Context

- Gemini 3.8 Flash: 46.3 (#24)
- GPT-5.5 Instant: 43.4 (#96)

| Benchmark | Gemini 3.8 Flash | GPT-5.5 Instant |
|---|---|---|
| LMArena Longer Query | 1508 | 1422 |

## Writing & Preference

- Gemini 3.8 Flash: 72.2 (#15)
- GPT-5.5 Instant: 61.8 (#85)

| Benchmark | Gemini 3.8 Flash | GPT-5.5 Instant |
|---|---|---|
| LMArena Text | 1499 | 1419 |
| LMArena Creative Writing | 1492 | 1419 |
| LMArena Multi-Turn | 1501 | 1433 |
| EQ-Bench Creative Writing | 1748 | — |

## FAQ

### Is Gemini 3.8 Flash better than GPT-5.5 Instant?

Gemini 3.8 Flash is the stronger model overall, scoring 61.8 to 42.7 on the Noometry Index.

### Is Gemini 3.8 Flash or GPT-5.5 Instant better for coding?

Gemini 3.8 Flash scores higher on coding benchmarks: 59.2 versus 44.3 in the Noometry coding category.

### How many benchmarks do Gemini 3.8 Flash and GPT-5.5 Instant share?

26 benchmarks have published results for both models. Gemini 3.8 Flash has 50 scored results on Noometry and GPT-5.5 Instant has 27.