# Gemini 3.1 Flash Lite vs Mercury 2.5

> Gemini 3.1 Flash Lite is the stronger model overall, scoring 40.8 to 33.5 on the Noometry Index. Mercury 2.5 costs 8.3× less per token, which makes it the better buy when Gemini 3.1 Flash Lite's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/gemini-3-1-flash-lite-vs-mercury-2-5
- Last updated: 2026-10-12
- Shared benchmarks: 3

## Summary

- They share 3 benchmarks with published results for both. Gemini 3.1 Flash Lite scores higher in 2 categories and Mercury 2.5 in 1 category; 2 gaps are clear of the uncertainty.
- The widest gap is in math, where Gemini 3.1 Flash Lite leads 40.7 to 23.3.
- Mercury 2.5 is cheaper at $0.04 / $0.15 per million input/output tokens, against $0.25 / $1.50 for Gemini 3.1 Flash Lite.
- Gemini 3.1 Flash Lite accepts more context: 1.05M tokens versus 260K.

## Snapshot

| | Gemini 3.1 Flash Lite | Mercury 2.5 |
|---|---|---|
| Provider | Google | Inception |
| Noometry Index | 40.8 | 33.5 |
| Rank | 144 | 242 |
| Context | 1.05M | 260K |
| Input $/M | $0.25 | $0.04 |
| Output $/M | $1.50 | $0.15 |
| Weights | Proprietary | Proprietary |

## Coding

- Gemini 3.1 Flash Lite: 37.8 (#188)
- Mercury 2.5: 39.5 (#156)

| Benchmark | Gemini 3.1 Flash Lite | Mercury 2.5 |
|---|---|---|
| SciCode | 41.9% | 38.5% |
| ALE-Bench | 797.73 | 301.65 |
| LMArena WebDev | 1256 | — |
| WeirdML | 52.2% | — |
| LMArena Coding | 1400 | — |

## Agentic & Tool Use

- Gemini 3.1 Flash Lite: 30.2 (#79)
- Mercury 2.5: —

| Benchmark | Gemini 3.1 Flash Lite | Mercury 2.5 |
|---|---|---|
| DeepResearch Bench | 37.3% | — |

## Reasoning

- Gemini 3.1 Flash Lite: 22.9 (#186)
- Mercury 2.5: 22.4 (#193)

| Benchmark | Gemini 3.1 Flash Lite | Mercury 2.5 |
|---|---|---|
| CritPt | 1.1% | 0% |
| Kagi LLM Benchmark | 67.2% | — |
| NYT Connections (extended) | 8.2% | — |
| Chess Puzzles | 25% | — |
| EnigmaEval | 3% | — |
| Thematic Generalization | 63.3% | — |
| LMArena Hard Prompts | 1407 | — |
| DTBench | 76.8% | — |
| LMCA | 35% | — |
| Epoch Capabilities Index | 144.47 | — |
| ForecastBench | 54.4 | — |

## Math

- Gemini 3.1 Flash Lite: 40.7 (#90)
- Mercury 2.5: 23.3 (#272)

| Benchmark | Gemini 3.1 Flash Lite | Mercury 2.5 |
|---|---|---|
| FrontierMath (Tiers 1-3) | 27.7% | — |
| OTIS Mock AIME 2024-2025 | 80% | — |
| ProofBench | — | 3% |
| LMArena Math | 1428 | — |

## Knowledge

- Gemini 3.1 Flash Lite: 41.9 (#104)
- Mercury 2.5: —

| Benchmark | Gemini 3.1 Flash Lite | Mercury 2.5 |
|---|---|---|
| GPQA Diamond | 81.8% | — |
| Humanity's Last Exam | 8.6% | — |
| Vectara Hallucination Rate | 8.2% | — |
| LMArena Expert | 1398 | — |

## Multimodal

- Gemini 3.1 Flash Lite: 39.4 (#60)
- Mercury 2.5: —

| Benchmark | Gemini 3.1 Flash Lite | Mercury 2.5 |
|---|---|---|
| LMArena Vision | 1240 | — |

## Multilingual

- Gemini 3.1 Flash Lite: 52.3 (#86)
- Mercury 2.5: —

| Benchmark | Gemini 3.1 Flash Lite | Mercury 2.5 |
|---|---|---|
| LMArena Non-English | 1411 | — |
| LMArena Chinese | 1461 | — |
| LMArena French | 1424 | — |
| LMArena German | 1429 | — |
| LMArena Japanese | 1413 | — |
| LMArena Korean | 1392 | — |
| LMArena Russian | 1420 | — |
| LMArena Spanish | 1421 | — |

## Instruction Following

- Gemini 3.1 Flash Lite: 72.7 (#131)
- Mercury 2.5: —

| Benchmark | Gemini 3.1 Flash Lite | Mercury 2.5 |
|---|---|---|
| LMArena Instruction Following | 1377 | — |

## Long Context

- Gemini 3.1 Flash Lite: 42.5 (#122)
- Mercury 2.5: —

| Benchmark | Gemini 3.1 Flash Lite | Mercury 2.5 |
|---|---|---|
| LMArena Longer Query | 1394 | — |

## Writing & Preference

- Gemini 3.1 Flash Lite: 60.9 (#94)
- Mercury 2.5: —

| Benchmark | Gemini 3.1 Flash Lite | Mercury 2.5 |
|---|---|---|
| LMArena Text | 1416 | — |
| LMArena Creative Writing | 1401 | — |
| LMArena Multi-Turn | 1417 | — |

## FAQ

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

Gemini 3.1 Flash Lite is the stronger model overall, scoring 40.8 to 33.5 on the Noometry Index. Mercury 2.5 costs 8.3× less per token, which makes it the better buy when Gemini 3.1 Flash Lite's lead doesn't matter for your workload.

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

Mercury 2.5 is cheaper. It lists at $0.04 per million input tokens and $0.15 per million output tokens; Gemini 3.1 Flash Lite lists at $0.25 and $1.50.

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

Mercury 2.5 scores higher on coding benchmarks: 39.5 versus 37.8 in the Noometry coding category.

### Which has the bigger context window?

Gemini 3.1 Flash Lite does, with 1.05M tokens against 260K.

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

3 benchmarks have published results for both models. Gemini 3.1 Flash Lite has 38 scored results on Noometry and Mercury 2.5 has 4.