# Grok 3 vs Step 3.5 Flash

> Step 3.5 Flash is the stronger model overall, scoring 42.3 to 39.9 on the Noometry Index.

- Canonical page: https://noometry.com/compare/grok-3-vs-step-3-5-flash
- Last updated: 2026-10-12
- Shared benchmarks: 17

## Summary

- They share 17 benchmarks with published results for both. Grok 3 scores higher in 3 categories and Step 3.5 Flash in 5 categories; 7 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Step 3.5 Flash leads 22.2 to 13.7.
- Step 3.5 Flash has downloadable open weights; the other is API-only.

## Snapshot

| | Grok 3 | Step 3.5 Flash |
|---|---|---|
| Provider | xAI | StepFun |
| Noometry Index | 39.9 | 42.3 |
| Rank | 157 | 116 |
| Context | — | 256K |
| Input $/M | — | $0.10 |
| Output $/M | — | $0.30 |
| Weights | Proprietary | Open |

## Coding

- Grok 3: 41.9 (#115)
- Step 3.5 Flash: 42.4 (#105)

| Benchmark | Grok 3 | Step 3.5 Flash |
|---|---|---|
| LMArena Coding | 1432 | 1436 |
| Aider Polyglot | 53.3% | — |
| WeirdML | 37.2% | — |

## Agentic & Tool Use

- Grok 3: 30.5 (#76)
- Step 3.5 Flash: —

| Benchmark | Grok 3 | Step 3.5 Flash |
|---|---|---|
| BALROG | 29.5% | — |

## Reasoning

- Grok 3: 13.7 (#333)
- Step 3.5 Flash: 22.2 (#202)

| Benchmark | Grok 3 | Step 3.5 Flash |
|---|---|---|
| LMArena Hard Prompts | 1434 | 1411 |
| ARC-AGI-2 | 0% | — |
| SimpleBench | 36.1% | — |
| Kagi LLM Benchmark | 61.3% | — |
| NYT Connections (extended) | — | 28.4% |
| ARC-AGI-1 | 5.5% | — |
| Epoch Capabilities Index | 138.33 | — |

## Math

- Grok 3: 38.0 (#145)
- Step 3.5 Flash: 42.6 (#84)

| Benchmark | Grok 3 | Step 3.5 Flash |
|---|---|---|
| LMArena Math | 1391 | 1408 |
| MathArena Final-Answer Competitions | — | 66.8% |
| OTIS Mock AIME 2024-2025 | 55.6% | — |
| Omni-MATH | 46.4% | — |
| MATH Level 5 | 88.7% | — |
| FrontierMath (Feb 2025 set) | 3.8% | — |
| FrontierMath Tier 4 (v1) | 0% | — |

## Knowledge

- Grok 3: 46.2 (#82)
- Step 3.5 Flash: 39.6 (#132)

| Benchmark | Grok 3 | Step 3.5 Flash |
|---|---|---|
| LMArena Expert | 1421 | 1421 |
| GPQA Diamond | 75.8% | — |
| MMLU-Pro | 78.8% | — |
| Confabulations | 14.2% | — |
| Vectara Hallucination Rate | 5.8% | — |
| GPQA (HELM) | 65% | — |

## Multilingual

- Grok 3: 52.3 (#87)
- Step 3.5 Flash: 50.5 (#119)

| Benchmark | Grok 3 | Step 3.5 Flash |
|---|---|---|
| LMArena Non-English | 1410 | 1385 |
| LMArena Chinese | 1448 | 1447 |
| LMArena French | 1460 | 1421 |
| LMArena German | 1431 | 1405 |
| LMArena Japanese | 1387 | 1354 |
| LMArena Korean | 1373 | 1352 |
| LMArena Russian | 1416 | 1385 |
| LMArena Spanish | 1417 | 1419 |

## Instruction Following

- Grok 3: 75.0 (#73)
- Step 3.5 Flash: 73.1 (#124)

| Benchmark | Grok 3 | Step 3.5 Flash |
|---|---|---|
| LMArena Instruction Following | 1409 | 1385 |
| IFEval | 88.4% | — |

## Long Context

- Grok 3: 38.7 (#192)
- Step 3.5 Flash: 42.8 (#117)

| Benchmark | Grok 3 | Step 3.5 Flash |
|---|---|---|
| LMArena Longer Query | 1439 | 1402 |
| Fiction.LiveBench | 58.3% | — |

## Writing & Preference

- Grok 3: 55.8 (#141)
- Step 3.5 Flash: 58.8 (#113)

| Benchmark | Grok 3 | Step 3.5 Flash |
|---|---|---|
| LMArena Text | 1426 | 1403 |
| LMArena Creative Writing | 1414 | 1357 |
| LMArena Multi-Turn | 1425 | 1405 |
| Short-Story Creative Writing | 76.4% | — |
| EQ-Bench Creative Writing | 1186 | — |
| WildBench | 84.9% | — |

## FAQ

### Is Grok 3 better than Step 3.5 Flash?

Step 3.5 Flash is the stronger model overall, scoring 42.3 to 39.9 on the Noometry Index.

### Is Grok 3 or Step 3.5 Flash better for coding?

They score almost the same on coding (41.9 vs 42.4); test both on your own repository before choosing.

### How many benchmarks do Grok 3 and Step 3.5 Flash share?

17 benchmarks have published results for both models. Grok 3 has 40 scored results on Noometry and Step 3.5 Flash has 19.