# Gemini 2.5 Pro vs Gemini 3.1 Flash Lite

> Gemini 2.5 Pro is the stronger model overall, scoring 44.9 to 40.4 on the Noometry Index. Gemini 3.1 Flash Lite costs 6.1× less per token, which makes it the better buy when Gemini 2.5 Pro's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/gemini-2-5-pro-vs-gemini-3-1-flash-lite
- Last updated: 2026-10-10
- Shared benchmarks: 36

## Summary

- They share 36 benchmarks with published results for both. Gemini 2.5 Pro scores higher in 8 categories and Gemini 3.1 Flash Lite in 2 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in long context, where Gemini 2.5 Pro leads 59.7 to 42.5.
- The biggest single-benchmark swing is Humanity's Last Exam: 21.6% for Gemini 2.5 Pro and 8.6% for Gemini 3.1 Flash Lite.
- Gemini 3.1 Flash Lite is cheaper at $0.25 / $1.50 per million input/output tokens, against $1.25 / $10 for Gemini 2.5 Pro.

## Snapshot

| | Gemini 2.5 Pro | Gemini 3.1 Flash Lite |
|---|---|---|
| Provider | Google | Google |
| Noometry Index | 44.9 | 40.4 |
| Rank | 67 | 141 |
| Context | 1.05M | 1.05M |
| Input $/M | $1.25 | $0.25 |
| Output $/M | $10 | $1.50 |
| Weights | Proprietary | Proprietary |

## Coding

- Gemini 2.5 Pro: 42.8 (#86)
- Gemini 3.1 Flash Lite: 37.5 (#179)

| Benchmark | Gemini 2.5 Pro | Gemini 3.1 Flash Lite |
|---|---|---|
| LMArena WebDev | 1227 | 1256 |
| SciCode | 42.8% | 41.9% |
| WeirdML | 54% | 52.2% |
| LMArena Coding | 1452 | 1400 |
| ALE-Bench | 785.52 | 797.73 |
| SWE-bench Verified | 57.6% | — |
| SWE-bench Verified (bash only) | 53.6% | — |
| Aider Polyglot | 83.1% | — |
| GSO | 3.9% | — |
| LiveBench Coding | 85.9% | — |
| CadEval | 64% | — |
| AlgoTune | 1.51 | — |

## Agentic & Tool Use

- Gemini 2.5 Pro: 29.1 (#81)
- Gemini 3.1 Flash Lite: 29.9 (#72)

| Benchmark | Gemini 2.5 Pro | Gemini 3.1 Flash Lite |
|---|---|---|
| DeepResearch Bench | 42.8% | 37.3% |
| Terminal-Bench | 32.6% | — |
| GDPval | 23.3% | — |
| Remote Labor Index | 0.8% | — |
| TheAgentCompany | 30.3% | — |
| τ²-bench Banking | 13.7% | — |
| BALROG | 43.3% | — |
| LMArena Search | 1142 | — |
| METR Time Horizons | 55.4% | — |
| Vending-Bench 2 | 573.64 | — |

## Reasoning

- Gemini 2.5 Pro: 28.8 (#85)
- Gemini 3.1 Flash Lite: 22.3 (#181)

| Benchmark | Gemini 2.5 Pro | Gemini 3.1 Flash Lite |
|---|---|---|
| Kagi LLM Benchmark | 70.3% | 67.2% |
| CritPt | 2% | 1.1% |
| Chess Puzzles | 20% | 25% |
| EnigmaEval | 5.6% | 3% |
| LMArena Hard Prompts | 1455 | 1407 |
| DTBench | 82.4% | 76.8% |
| LMCA | 34.8% | 35% |
| Epoch Capabilities Index | 145.32 | 144.45 |
| ForecastBench | 61.3 | 54.4 |
| ARC-AGI-2 | 4.9% | — |
| SimpleBench | 62.4% | — |
| NYT Connections (extended) | — | 8.2% |
| ARC-AGI-1 | 41% | — |
| Thematic Generalization | — | 63.3% |
| LiveBench Reasoning | 89.8% | — |
| LiveBench Data Analysis | 79.9% | — |
| LiveBench | 82.3% | — |

## Math

- Gemini 2.5 Pro: 31.9 (#191)
- Gemini 3.1 Flash Lite: 39.5 (#82)

| Benchmark | Gemini 2.5 Pro | Gemini 3.1 Flash Lite |
|---|---|---|
| FrontierMath (Tiers 1-3) | 24.6% | 27.7% |
| OTIS Mock AIME 2024-2025 | 84.7% | 80% |
| LMArena Math | 1450 | 1427 |
| FrontierMath Tier 4 | 0% | — |
| Omni-MATH | 41.6% | — |
| LiveBench Math | 90.2% | — |
| MATH Level 5 | 95.9% | — |
| FrontierMath (Feb 2025 set) | 14.1% | — |
| FrontierMath Tier 4 (v1) | 4.2% | — |

## Knowledge

- Gemini 2.5 Pro: 55.8 (#41)
- Gemini 3.1 Flash Lite: 41.7 (#95)

| Benchmark | Gemini 2.5 Pro | Gemini 3.1 Flash Lite |
|---|---|---|
| GPQA Diamond | 85.3% | 81.8% |
| Humanity's Last Exam | 21.6% | 8.6% |
| Vectara Hallucination Rate | 7% | 8.2% |
| LMArena Expert | 1452 | 1397 |
| MMLU-Pro | 86.3% | — |
| Confabulations | 10.6% | — |
| GPQA (HELM) | 74.9% | — |

## Multimodal

- Gemini 2.5 Pro: 44.5 (#16)
- Gemini 3.1 Flash Lite: 38.7 (#57)

| Benchmark | Gemini 2.5 Pro | Gemini 3.1 Flash Lite |
|---|---|---|
| LMArena Vision | 1263 | 1240 |
| GeoBench | 86% | — |
| VPCT | 48% | — |
| LMArena Document | 1421 | — |
| SpatialViz-Bench | 44.7% | — |

## Multilingual

- Gemini 2.5 Pro: 55.5 (#30)
- Gemini 3.1 Flash Lite: 52.5 (#82)

| Benchmark | Gemini 2.5 Pro | Gemini 3.1 Flash Lite |
|---|---|---|
| LMArena Non-English | 1452 | 1410 |
| LMArena Chinese | 1507 | 1461 |
| LMArena French | 1473 | 1423 |
| LMArena German | 1487 | 1429 |
| LMArena Japanese | 1462 | 1411 |
| LMArena Korean | 1435 | 1393 |
| LMArena Russian | 1460 | 1420 |
| LMArena Spanish | 1473 | 1420 |

## Instruction Following

- Gemini 2.5 Pro: 75.2 (#71)
- Gemini 3.1 Flash Lite: 72.9 (#126)

| Benchmark | Gemini 2.5 Pro | Gemini 3.1 Flash Lite |
|---|---|---|
| LMArena Instruction Following | 1436 | 1376 |
| LiveBench Instruction Following | 80.6% | — |
| IFEval | 84% | — |

## Long Context

- Gemini 2.5 Pro: 59.7 (#5)
- Gemini 3.1 Flash Lite: 42.5 (#117)

| Benchmark | Gemini 2.5 Pro | Gemini 3.1 Flash Lite |
|---|---|---|
| LMArena Longer Query | 1449 | 1394 |
| Fiction.LiveBench | 91.7% | — |

## Writing & Preference

- Gemini 2.5 Pro: 63.9 (#60)
- Gemini 3.1 Flash Lite: 61.0 (#90)

| Benchmark | Gemini 2.5 Pro | Gemini 3.1 Flash Lite |
|---|---|---|
| LMArena Text | 1458 | 1416 |
| LMArena Creative Writing | 1453 | 1401 |
| LMArena Multi-Turn | 1453 | 1417 |
| Short-Story Creative Writing | 83.8% | — |
| EQ-Bench Creative Writing | 1421 | — |
| WildBench | 85.7% | — |
| LiveBench Language | 67.8% | — |

## FAQ

### Is Gemini 2.5 Pro better than Gemini 3.1 Flash Lite?

Gemini 2.5 Pro is the stronger model overall, scoring 44.9 to 40.4 on the Noometry Index. Gemini 3.1 Flash Lite costs 6.1× less per token, which makes it the better buy when Gemini 2.5 Pro's lead doesn't matter for your workload.

### Which is cheaper, Gemini 2.5 Pro or Gemini 3.1 Flash Lite?

Gemini 3.1 Flash Lite is cheaper. It lists at $0.25 per million input tokens and $1.50 per million output tokens; Gemini 2.5 Pro lists at $1.25 and $10.

### Is Gemini 2.5 Pro or Gemini 3.1 Flash Lite better for coding?

Gemini 2.5 Pro scores higher on coding benchmarks: 42.8 versus 37.5 in the Noometry coding category.

### Which has the bigger context window?

Both accept 1.05M tokens.

### How many benchmarks do Gemini 2.5 Pro and Gemini 3.1 Flash Lite share?

36 benchmarks have published results for both models. Gemini 2.5 Pro has 78 scored results on Noometry and Gemini 3.1 Flash Lite has 38.