# Gemini 2.5 Flash vs Grok 4.3

> Grok 4.3 is the stronger model overall, scoring 43.8 to 39.3 on the Noometry Index. Gemini 2.5 Flash costs 1.8× less per token, which makes it the better buy when Grok 4.3's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/gemini-2-5-flash-vs-grok-4-3
- Last updated: 2026-10-10
- Shared benchmarks: 27

## Summary

- They share 27 benchmarks with published results for both. Gemini 2.5 Flash scores higher in 5 categories and Grok 4.3 in 5 categories; 10 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Grok 4.3 leads 35.9 to 18.1.
- The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 73.1% for Gemini 2.5 Flash and 93.3% for Grok 4.3.
- Gemini 2.5 Flash is cheaper at $0.30 / $2.50 per million input/output tokens, against $1.25 / $2.50 for Grok 4.3.
- Gemini 2.5 Flash accepts more context: 1.05M tokens versus 1M.

## Snapshot

| | Gemini 2.5 Flash | Grok 4.3 |
|---|---|---|
| Provider | Google | xAI |
| Noometry Index | 39.3 | 43.8 |
| Rank | 170 | 86 |
| Context | 1.05M | 1M |
| Input $/M | $0.30 | $1.25 |
| Output $/M | $2.50 | $2.50 |
| Weights | Proprietary | Proprietary |

## Coding

- Gemini 2.5 Flash: 35.8 (#220)
- Grok 4.3: 41.6 (#121)

| Benchmark | Gemini 2.5 Flash | Grok 4.3 |
|---|---|---|
| WeirdML | 41.9% | 49.9% |
| LMArena Coding | 1424 | 1415 |
| ALE-Bench | 661.88 | 944.17 |
| SWE-bench Verified (bash only) | 28.7% | — |
| Aider Polyglot | 55.1% | — |
| LMArena WebDev | — | 1357 |
| SciCode | — | 47.3% |

## Agentic & Tool Use

- Gemini 2.5 Flash: 30.8 (#74)
- Grok 4.3: 27.7 (#99)

| Benchmark | Gemini 2.5 Flash | Grok 4.3 |
|---|---|---|
| Vending-Bench 2 | 548.84 | 35.26 |
| Terminal-Bench | 17.1% | — |
| Berkeley Function Calling Leaderboard | 56.2% | — |
| TheAgentCompany | 41.1% | — |
| BALROG | 33.5% | — |
| GDP.pdf | — | 8% |
| LMArena Search | — | 1165 |

## Reasoning

- Gemini 2.5 Flash: 18.1 (#286)
- Grok 4.3: 35.9 (#68)

| Benchmark | Gemini 2.5 Flash | Grok 4.3 |
|---|---|---|
| CritPt | 1.1% | 8% |
| LMArena Hard Prompts | 1422 | 1396 |
| DTBench | 76.5% | 90.7% |
| LMCA | 27.5% | 38.3% |
| Epoch Capabilities Index | 143.03 | 149.16 |
| ForecastBench | 60.6 | 60.3 |
| ARC-AGI-2 | 2.5% | — |
| SimpleBench | 41.2% | — |
| Kagi LLM Benchmark | 56.8% | — |
| NYT Connections (extended) | — | 55.2% |
| ARC-AGI-1 | 33.3% | — |
| Chess Puzzles | — | 25% |
| EnigmaEval | 2.7% | — |

## Math

- Gemini 2.5 Flash: 39.9 (#98)
- Grok 4.3: 46.0 (#74)

| Benchmark | Gemini 2.5 Flash | Grok 4.3 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 73.1% | 93.3% |
| LMArena Math | 1415 | 1388 |
| FrontierMath (Tiers 1-3) | — | 42.8% |
| FrontierMath Tier 4 | — | 14.6% |
| ProofBench | — | 11% |
| Omni-MATH | 38.5% | — |
| FrontierMath (Feb 2025 set) | 4.8% | — |
| FrontierMath Tier 4 (v1) | 4.2% | — |

## Knowledge

- Gemini 2.5 Flash: 36.4 (#168)
- Grok 4.3: 52.5 (#62)

| Benchmark | Gemini 2.5 Flash | Grok 4.3 |
|---|---|---|
| LMArena Expert | 1426 | 1385 |
| GPQA Diamond | — | 88.8% |
| Humanity's Last Exam | 12.1% | — |
| SimpleQA Verified | — | 33.2% |
| MMLU-Pro | 63.9% | — |
| Confabulations | 16.8% | — |
| Vectara Hallucination Rate | 7.8% | — |
| GPQA (HELM) | 39% | — |

## Multimodal

- Gemini 2.5 Flash: 41.8 (#32)
- Grok 4.3: 31.6 (#104)

| Benchmark | Gemini 2.5 Flash | Grok 4.3 |
|---|---|---|
| LMArena Vision | 1253 | 1229 |
| GeoBench | 76% | — |
| VPCT | 46.2% | — |
| Blueprint-Bench 2 | — | 0% |
| SpatialViz-Bench | 36.9% | — |

## Multilingual

- Gemini 2.5 Flash: 52.3 (#88)
- Grok 4.3: 50.5 (#120)

| Benchmark | Gemini 2.5 Flash | Grok 4.3 |
|---|---|---|
| LMArena Non-English | 1409 | 1385 |
| LMArena Chinese | 1450 | 1422 |
| LMArena French | 1433 | 1412 |
| LMArena German | 1418 | 1395 |
| LMArena Japanese | 1405 | 1379 |
| LMArena Korean | 1385 | 1356 |
| LMArena Russian | 1415 | 1399 |
| LMArena Spanish | 1421 | 1398 |

## Instruction Following

- Gemini 2.5 Flash: 75.7 (#54)
- Grok 4.3: 72.1 (#140)

| Benchmark | Gemini 2.5 Flash | Grok 4.3 |
|---|---|---|
| LMArena Instruction Following | 1405 | 1366 |
| IFEval | 89.8% | — |

## Long Context

- Gemini 2.5 Flash: 47.5 (#17)
- Grok 4.3: 42.5 (#123)

| Benchmark | Gemini 2.5 Flash | Grok 4.3 |
|---|---|---|
| LMArena Longer Query | 1419 | 1393 |
| Fiction.LiveBench | 77.8% | — |

## Writing & Preference

- Gemini 2.5 Flash: 53.8 (#157)
- Grok 4.3: 58.5 (#118)

| Benchmark | Gemini 2.5 Flash | Grok 4.3 |
|---|---|---|
| LMArena Text | 1417 | 1397 |
| LMArena Creative Writing | 1400 | 1380 |
| LMArena Multi-Turn | 1408 | 1406 |
| Short-Story Creative Writing | 76.5% | — |
| EQ-Bench Creative Writing | 1137 | — |
| WildBench | 81.7% | — |
| EQ-Bench 4 | — | 1075 |

## FAQ

### Is Gemini 2.5 Flash better than Grok 4.3?

Grok 4.3 is the stronger model overall, scoring 43.8 to 39.3 on the Noometry Index. Gemini 2.5 Flash costs 1.8× less per token, which makes it the better buy when Grok 4.3's lead doesn't matter for your workload.

### Which is cheaper, Gemini 2.5 Flash or Grok 4.3?

Gemini 2.5 Flash is cheaper. It lists at $0.30 per million input tokens and $2.50 per million output tokens; Grok 4.3 lists at $1.25 and $2.50.

### Is Gemini 2.5 Flash or Grok 4.3 better for coding?

Grok 4.3 scores higher on coding benchmarks: 41.6 versus 35.8 in the Noometry coding category.

### Which has the bigger context window?

Gemini 2.5 Flash does, with 1.05M tokens against 1M.

### How many benchmarks do Gemini 2.5 Flash and Grok 4.3 share?

27 benchmarks have published results for both models. Gemini 2.5 Flash has 54 scored results on Noometry and Grok 4.3 has 40.