# Gemini 1.5 Flash 8B vs Gemini 2.5 Flash

> Gemini 2.5 Flash is the stronger model overall, scoring 39.0 to 29.7 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gemini-1-5-flash-8b-vs-gemini-2-5-flash
- Last updated: 2026-10-10
- Shared benchmarks: 20

## Summary

- They share 20 benchmarks with published results for both. Gemini 1.5 Flash 8B scores higher in 1 category and Gemini 2.5 Flash in 8 categories; 7 gaps are clear of the uncertainty.
- The widest gap is in math, where Gemini 2.5 Flash leads 38.1 to 13.3.
- The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 4.6% for Gemini 1.5 Flash 8B and 73.1% for Gemini 2.5 Flash.

## Snapshot

| | Gemini 1.5 Flash 8B | Gemini 2.5 Flash |
|---|---|---|
| Provider | Google | Google |
| Noometry Index | 29.7 | 39.0 |
| Rank | 292 | 162 |
| Context | — | 1.05M |
| Input $/M | — | $0.30 |
| Output $/M | — | $2.50 |
| Weights | Proprietary | Proprietary |

## Coding

- Gemini 1.5 Flash 8B: 34.9 (#221)
- Gemini 2.5 Flash: 35.5 (#210)

| Benchmark | Gemini 1.5 Flash 8B | Gemini 2.5 Flash |
|---|---|---|
| LMArena Coding | 1218 | 1424 |
| SWE-bench Verified (bash only) | — | 28.7% |
| Aider Polyglot | — | 55.1% |
| WeirdML | — | 41.9% |
| ALE-Bench | — | 661.88 |

## Agentic & Tool Use

- Gemini 1.5 Flash 8B: —
- Gemini 2.5 Flash: 30.6 (#67)

| Benchmark | Gemini 1.5 Flash 8B | Gemini 2.5 Flash |
|---|---|---|
| Terminal-Bench | — | 17.1% |
| Berkeley Function Calling Leaderboard | — | 56.2% |
| TheAgentCompany | — | 41.1% |
| BALROG | — | 33.5% |
| Vending-Bench 2 | — | 548.84 |

## Reasoning

- Gemini 1.5 Flash 8B: 19.2 (#242)
- Gemini 2.5 Flash: 18.2 (#271)

| Benchmark | Gemini 1.5 Flash 8B | Gemini 2.5 Flash |
|---|---|---|
| LMArena Hard Prompts | 1210 | 1422 |
| DTBench | 50% | 76.5% |
| ARC-AGI-2 | — | 2.5% |
| SimpleBench | — | 41.2% |
| Kagi LLM Benchmark | — | 56.8% |
| ARC-AGI-1 | — | 33.3% |
| CritPt | — | 1.1% |
| EnigmaEval | — | 2.7% |
| LMCA | — | 27.5% |
| Epoch Capabilities Index | — | 143.04 |
| ForecastBench | — | 60.6 |

## Math

- Gemini 1.5 Flash 8B: 13.3 (#296)
- Gemini 2.5 Flash: 38.1 (#87)

| Benchmark | Gemini 1.5 Flash 8B | Gemini 2.5 Flash |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 4.6% | 73.1% |
| LMArena Math | 1207 | 1415 |
| Omni-MATH | — | 38.5% |
| FrontierMath (Feb 2025 set) | — | 4.8% |
| FrontierMath Tier 4 (v1) | — | 4.2% |

## Knowledge

- Gemini 1.5 Flash 8B: 16.0 (#285)
- Gemini 2.5 Flash: 36.1 (#162)

| Benchmark | Gemini 1.5 Flash 8B | Gemini 2.5 Flash |
|---|---|---|
| LMArena Expert | 1185 | 1426 |
| GPQA Diamond | 33% | — |
| Humanity's Last Exam | — | 12.1% |
| MMLU-Pro | — | 63.9% |
| Confabulations | — | 16.8% |
| Vectara Hallucination Rate | — | 7.8% |
| GPQA (HELM) | — | 39% |

## Multimodal

- Gemini 1.5 Flash 8B: 27.6 (#110)
- Gemini 2.5 Flash: 41.2 (#31)

| Benchmark | Gemini 1.5 Flash 8B | Gemini 2.5 Flash |
|---|---|---|
| LMArena Vision | 1044 | 1254 |
| GeoBench | — | 76% |
| VPCT | — | 46.2% |
| SpatialViz-Bench | — | 36.9% |

## Multilingual

- Gemini 1.5 Flash 8B: 38.6 (#224)
- Gemini 2.5 Flash: 52.5 (#83)

| Benchmark | Gemini 1.5 Flash 8B | Gemini 2.5 Flash |
|---|---|---|
| LMArena Non-English | 1215 | 1410 |
| LMArena Chinese | 1231 | 1450 |
| LMArena French | 1233 | 1433 |
| LMArena German | 1206 | 1419 |
| LMArena Japanese | 1150 | 1403 |
| LMArena Korean | 1140 | 1385 |
| LMArena Russian | 1236 | 1415 |
| LMArena Spanish | 1212 | 1421 |

## Instruction Following

- Gemini 1.5 Flash 8B: 63.1 (#231)
- Gemini 2.5 Flash: 75.9 (#50)

| Benchmark | Gemini 1.5 Flash 8B | Gemini 2.5 Flash |
|---|---|---|
| LMArena Instruction Following | 1199 | 1405 |
| IFEval | — | 89.8% |

## Long Context

- Gemini 1.5 Flash 8B: 36.9 (#220)
- Gemini 2.5 Flash: 47.5 (#16)

| Benchmark | Gemini 1.5 Flash 8B | Gemini 2.5 Flash |
|---|---|---|
| LMArena Longer Query | 1219 | 1419 |
| Fiction.LiveBench | — | 77.8% |

## Writing & Preference

- Gemini 1.5 Flash 8B: 43.0 (#227)
- Gemini 2.5 Flash: 54.0 (#153)

| Benchmark | Gemini 1.5 Flash 8B | Gemini 2.5 Flash |
|---|---|---|
| LMArena Text | 1226 | 1417 |
| LMArena Creative Writing | 1218 | 1400 |
| LMArena Multi-Turn | 1185 | 1408 |
| Short-Story Creative Writing | — | 76.5% |
| EQ-Bench Creative Writing | — | 1137 |
| WildBench | — | 81.7% |

## FAQ

### Is Gemini 1.5 Flash 8B better than Gemini 2.5 Flash?

Gemini 2.5 Flash is the stronger model overall, scoring 39.0 to 29.7 on the Noometry Index.

### Is Gemini 1.5 Flash 8B or Gemini 2.5 Flash better for coding?

They score almost the same on coding (34.9 vs 35.5); test both on your own repository before choosing.

### How many benchmarks do Gemini 1.5 Flash 8B and Gemini 2.5 Flash share?

20 benchmarks have published results for both models. Gemini 1.5 Flash 8B has 21 scored results on Noometry and Gemini 2.5 Flash has 54.