# Solar Pro4 vs Step 5 Preview

> Step 5 Preview is the stronger model overall, scoring 43.8 to 41.5 on the Noometry Index. Solar Pro4 costs 2.7× less per token, which makes it the better buy when Step 5 Preview's lead doesn't matter for your workload.

- Canonical page: https://noometry.com/compare/solar-pro4-vs-step-5-preview
- Last updated: 2026-10-10
- Shared benchmarks: 1

## Summary

- They share 1 benchmark with published results for both. Solar Pro4 scores higher in 0 categories and Step 5 Preview in 2 categories; 2 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Step 5 Preview leads 38.0 to 27.3.
- Solar Pro4 is cheaper at $0.30 / $1.20 per million input/output tokens, against $1 / $2.70 for Step 5 Preview.
- Step 5 Preview accepts more context: 1.02M tokens versus 524K.

## Snapshot

| | Solar Pro4 | Step 5 Preview |
|---|---|---|
| Provider | Upstage | StepFun |
| Noometry Index | 41.5 | 43.8 |
| Rank | 123 | 78 |
| Context | 524K | 1.02M |
| Input $/M | $0.30 | $1 |
| Output $/M | $1.20 | $2.70 |
| Weights | Proprietary | Proprietary |

## Coding

- Solar Pro4: 39.9 (#135)
- Step 5 Preview: 50.6 (#40)

| Benchmark | Solar Pro4 | Step 5 Preview |
|---|---|---|
| LMArena WebDev | 1371 | 1569 |
| SciCode | — | 58.9% |
| LMArena Coding | 1439 | — |

## Reasoning

- Solar Pro4: 27.3 (#107)
- Step 5 Preview: 38.0 (#58)

| Benchmark | Solar Pro4 | Step 5 Preview |
|---|---|---|
| CritPt | — | 20.9% |
| LMArena Hard Prompts | 1398 | — |

## Math

- Solar Pro4: 36.1 (#129)
- Step 5 Preview: —

| Benchmark | Solar Pro4 | Step 5 Preview |
|---|---|---|
| LMArena Math | 1418 | — |

## Knowledge

- Solar Pro4: 39.0 (#128)
- Step 5 Preview: —

| Benchmark | Solar Pro4 | Step 5 Preview |
|---|---|---|
| LMArena Expert | 1421 | — |

## Multilingual

- Solar Pro4: 49.0 (#134)
- Step 5 Preview: —

| Benchmark | Solar Pro4 | Step 5 Preview |
|---|---|---|
| LMArena Non-English | 1362 | — |
| LMArena Chinese | 1417 | — |
| LMArena French | 1403 | — |
| LMArena German | 1351 | — |
| LMArena Japanese | 1300 | — |
| LMArena Korean | 1383 | — |
| LMArena Russian | 1360 | — |
| LMArena Spanish | 1408 | — |

## Instruction Following

- Solar Pro4: 72.8 (#128)
- Step 5 Preview: —

| Benchmark | Solar Pro4 | Step 5 Preview |
|---|---|---|
| LMArena Instruction Following | 1376 | — |

## Long Context

- Solar Pro4: 42.0 (#125)
- Step 5 Preview: —

| Benchmark | Solar Pro4 | Step 5 Preview |
|---|---|---|
| LMArena Longer Query | 1379 | — |

## Writing & Preference

- Solar Pro4: 56.7 (#133)
- Step 5 Preview: —

| Benchmark | Solar Pro4 | Step 5 Preview |
|---|---|---|
| LMArena Text | 1386 | — |
| LMArena Creative Writing | 1313 | — |
| LMArena Multi-Turn | 1391 | — |

## FAQ

### Is Solar Pro4 better than Step 5 Preview?

Step 5 Preview is the stronger model overall, scoring 43.8 to 41.5 on the Noometry Index. Solar Pro4 costs 2.7× less per token, which makes it the better buy when Step 5 Preview's lead doesn't matter for your workload.

### Which is cheaper, Solar Pro4 or Step 5 Preview?

Solar Pro4 is cheaper. It lists at $0.30 per million input tokens and $1.20 per million output tokens; Step 5 Preview lists at $1 and $2.70.

### Is Solar Pro4 or Step 5 Preview better for coding?

Step 5 Preview scores higher on coding benchmarks: 50.6 versus 39.9 in the Noometry coding category.

### Which has the bigger context window?

Step 5 Preview does, with 1.02M tokens against 524K.

### How many benchmarks do Solar Pro4 and Step 5 Preview share?

1 benchmark has published results for both models. Solar Pro4 has 18 scored results on Noometry and Step 5 Preview has 3.