# Gemini 3.1 Flash Lite vs Grok 4.20 (Non-Reasoning)

> Grok 4.20 (Non-Reasoning) is the stronger model overall, scoring 48.6 to 40.8 on the Noometry Index. Gemini 3.1 Flash Lite costs 2.8× less per token, which makes it the better buy when Grok 4.20 (Non-Reasoning)'s lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/gemini-3-1-flash-lite-vs-grok-4-20
- Last updated: 2026-10-12
- Shared benchmarks: 32

## Summary

- They share 32 benchmarks with published results for both. Gemini 3.1 Flash Lite scores higher in 1 category and Grok 4.20 (Non-Reasoning) in 9 categories; 10 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Grok 4.20 (Non-Reasoning) leads 52.3 to 22.9.
- The biggest single-benchmark swing is NYT Connections (extended): 8.2% for Gemini 3.1 Flash Lite and 85.4% for Grok 4.20 (Non-Reasoning).
- Gemini 3.1 Flash Lite is cheaper at $0.25 / $1.50 per million input/output tokens, against $1.25 / $2.50 for Grok 4.20 (Non-Reasoning).
- Gemini 3.1 Flash Lite accepts more context: 1.05M tokens versus 1M.

## Snapshot

| | Gemini 3.1 Flash Lite | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| Provider | Google | xAI |
| Noometry Index | 40.8 | 48.6 |
| Rank | 144 | 54 |
| Context | 1.05M | 1M |
| Input $/M | $0.25 | $1.25 |
| Output $/M | $1.50 | $2.50 |
| Weights | Proprietary | Proprietary |

## Coding

- Gemini 3.1 Flash Lite: 37.8 (#188)
- Grok 4.20 (Non-Reasoning): 42.1 (#112)

| Benchmark | Gemini 3.1 Flash Lite | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| LMArena WebDev | 1256 | 1375 |
| WeirdML | 52.2% | 52.3% |
| LMArena Coding | 1400 | 1459 |
| ALE-Bench | 797.73 | 1,150 |
| SciCode | 41.9% | — |

## Agentic & Tool Use

- Gemini 3.1 Flash Lite: 30.2 (#79)
- Grok 4.20 (Non-Reasoning): 34.4 (#46)

| Benchmark | Gemini 3.1 Flash Lite | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| Terminal-Bench | — | 57.3% |
| τ²-bench Banking | — | 18% |
| DeepResearch Bench | 37.3% | — |
| LMArena Search | — | 1189 |
| Vending-Bench 2 | — | 4,663 |

## Reasoning

- Gemini 3.1 Flash Lite: 22.9 (#186)
- Grok 4.20 (Non-Reasoning): 52.3 (#32)

| Benchmark | Gemini 3.1 Flash Lite | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| Kagi LLM Benchmark | 67.2% | 75% |
| NYT Connections (extended) | 8.2% | 85.4% |
| Chess Puzzles | 25% | 24% |
| Thematic Generalization | 63.3% | 63.8% |
| LMArena Hard Prompts | 1407 | 1451 |
| DTBench | 76.8% | 90.1% |
| LMCA | 35% | 38.7% |
| Epoch Capabilities Index | 144.47 | 151.98 |
| ForecastBench | 54.4 | 61.4 |
| ARC-AGI-2 | — | 65.1% |
| ARC-AGI-1 | — | 89.5% |
| CritPt | 1.1% | — |
| EnigmaEval | 3% | — |

## Math

- Gemini 3.1 Flash Lite: 40.7 (#90)
- Grok 4.20 (Non-Reasoning): 48.2 (#65)

| Benchmark | Gemini 3.1 Flash Lite | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| FrontierMath (Tiers 1-3) | 27.7% | 44.9% |
| OTIS Mock AIME 2024-2025 | 80% | 92.2% |
| LMArena Math | 1428 | 1455 |
| FrontierMath Tier 4 | — | 17.1% |
| ProofBench | — | 14% |

## Knowledge

- Gemini 3.1 Flash Lite: 41.9 (#104)
- Grok 4.20 (Non-Reasoning): 52.8 (#60)

| Benchmark | Gemini 3.1 Flash Lite | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| GPQA Diamond | 81.8% | 89.3% |
| LMArena Expert | 1398 | 1439 |
| Humanity's Last Exam | 8.6% | — |
| SimpleQA Verified | — | 30.2% |
| Vectara Hallucination Rate | 8.2% | — |

## Multimodal

- Gemini 3.1 Flash Lite: 39.4 (#60)
- Grok 4.20 (Non-Reasoning): 33.3 (#98)

| Benchmark | Gemini 3.1 Flash Lite | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| LMArena Vision | 1240 | 1263 |
| Blueprint-Bench 2 | — | 0% |
| LMArena Document | — | 1416 |

## Multilingual

- Gemini 3.1 Flash Lite: 52.3 (#86)
- Grok 4.20 (Non-Reasoning): 54.5 (#40)

| Benchmark | Gemini 3.1 Flash Lite | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| LMArena Non-English | 1411 | 1441 |
| LMArena Chinese | 1461 | 1481 |
| LMArena French | 1424 | 1476 |
| LMArena German | 1429 | 1465 |
| LMArena Japanese | 1413 | 1449 |
| LMArena Korean | 1392 | 1417 |
| LMArena Russian | 1420 | 1458 |
| LMArena Spanish | 1421 | 1443 |

## Instruction Following

- Gemini 3.1 Flash Lite: 72.7 (#131)
- Grok 4.20 (Non-Reasoning): 74.8 (#83)

| Benchmark | Gemini 3.1 Flash Lite | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| LMArena Instruction Following | 1377 | 1420 |

## Long Context

- Gemini 3.1 Flash Lite: 42.5 (#122)
- Grok 4.20 (Non-Reasoning): 45.5 (#34)

| Benchmark | Gemini 3.1 Flash Lite | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| LMArena Longer Query | 1394 | 1437 |
| CL-bench | — | 22.2% |
| CL-bench Life | — | 11.9% |

## Writing & Preference

- Gemini 3.1 Flash Lite: 60.9 (#94)
- Grok 4.20 (Non-Reasoning): 65.7 (#44)

| Benchmark | Gemini 3.1 Flash Lite | Grok 4.20 (Non-Reasoning) |
|---|---|---|
| LMArena Text | 1416 | 1451 |
| LMArena Creative Writing | 1401 | 1438 |
| LMArena Multi-Turn | 1417 | 1456 |
| EQ-Bench Creative Writing | — | 1574 |

## FAQ

### Is Gemini 3.1 Flash Lite better than Grok 4.20 (Non-Reasoning)?

Grok 4.20 (Non-Reasoning) is the stronger model overall, scoring 48.6 to 40.8 on the Noometry Index. Gemini 3.1 Flash Lite costs 2.8× less per token, which makes it the better buy when Grok 4.20 (Non-Reasoning)'s lead doesn't matter for your workload.

### Which is cheaper, Gemini 3.1 Flash Lite or Grok 4.20 (Non-Reasoning)?

Gemini 3.1 Flash Lite is cheaper. It lists at $0.25 per million input tokens and $1.50 per million output tokens; Grok 4.20 (Non-Reasoning) lists at $1.25 and $2.50.

### Is Gemini 3.1 Flash Lite or Grok 4.20 (Non-Reasoning) better for coding?

Grok 4.20 (Non-Reasoning) scores higher on coding benchmarks: 42.1 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 1M.

### How many benchmarks do Gemini 3.1 Flash Lite and Grok 4.20 (Non-Reasoning) share?

32 benchmarks have published results for both models. Gemini 3.1 Flash Lite has 38 scored results on Noometry and Grok 4.20 (Non-Reasoning) has 46.