# DeepSeek-V3.1-Terminus vs Step 5 Preview

> Step 5 Preview is the stronger model overall, scoring 47.9 to 43.1 on the Noometry Index. DeepSeek-V3.1-Terminus costs 3.1× 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/deepseek-v3-1-terminus-vs-step-5-preview
- Last updated: 2026-10-10
- Shared benchmarks: 12

## Summary

- They share 12 benchmarks with published results for both. DeepSeek-V3.1-Terminus scores higher in 0 categories and Step 5 Preview in 7 categories; 7 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Step 5 Preview leads 40.0 to 26.4.
- The biggest single-benchmark swing is CritPt: 1.7% for DeepSeek-V3.1-Terminus and 20.9% for Step 5 Preview.
- DeepSeek-V3.1-Terminus is cheaper at $0.27 / $1 per million input/output tokens, against $1 / $2.70 for Step 5 Preview.
- Step 5 Preview accepts more context: 1.02M tokens versus 164K.
- DeepSeek-V3.1-Terminus has downloadable open weights; the other is API-only.

## Snapshot

| | DeepSeek-V3.1-Terminus | Step 5 Preview |
|---|---|---|
| Provider | DeepSeek | StepFun |
| Noometry Index | 43.1 | 47.9 |
| Rank | 97 | 58 |
| Context | 164K | 1.02M |
| Input $/M | $0.27 | $1 |
| Output $/M | $1 | $2.70 |
| Weights | Open | Proprietary |

## Coding

- DeepSeek-V3.1-Terminus: 42.0 (#113)
- Step 5 Preview: 51.8 (#36)

| Benchmark | DeepSeek-V3.1-Terminus | Step 5 Preview |
|---|---|---|
| SciCode | 40.6% | 58.9% |
| LMArena Coding | 1426 | 1480 |
| LMArena WebDev | — | 1564 |
| ALE-Bench | 745.17 | — |

## Reasoning

- DeepSeek-V3.1-Terminus: 26.4 (#133)
- Step 5 Preview: 40.0 (#57)

| Benchmark | DeepSeek-V3.1-Terminus | Step 5 Preview |
|---|---|---|
| CritPt | 1.7% | 20.9% |
| LMArena Hard Prompts | 1426 | 1465 |
| Kagi LLM Benchmark | 57.4% | — |
| DTBench | 81.3% | — |
| LMCA | 28.6% | — |

## Math

- DeepSeek-V3.1-Terminus: 38.5 (#137)
- Step 5 Preview: 46.1 (#72)

| Benchmark | DeepSeek-V3.1-Terminus | Step 5 Preview |
|---|---|---|
| LMArena Math | 1402 | 1470 |
| ProofBench | — | 42% |

## Knowledge

- DeepSeek-V3.1-Terminus: —
- Step 5 Preview: 41.2 (#112)

| Benchmark | DeepSeek-V3.1-Terminus | Step 5 Preview |
|---|---|---|
| LMArena Expert | — | 1470 |

## Multimodal

- DeepSeek-V3.1-Terminus: —
- Step 5 Preview: 41.0 (#41)

| Benchmark | DeepSeek-V3.1-Terminus | Step 5 Preview |
|---|---|---|
| LMArena Vision | — | 1267 |

## Multilingual

- DeepSeek-V3.1-Terminus: 52.1 (#92)
- Step 5 Preview: 53.8 (#54)

| Benchmark | DeepSeek-V3.1-Terminus | Step 5 Preview |
|---|---|---|
| LMArena Non-English | 1407 | 1432 |
| LMArena Russian | 1436 | 1436 |
| LMArena Chinese | — | 1519 |
| LMArena Spanish | — | 1439 |

## Instruction Following

- DeepSeek-V3.1-Terminus: 74.0 (#106)
- Step 5 Preview: 76.0 (#50)

| Benchmark | DeepSeek-V3.1-Terminus | Step 5 Preview |
|---|---|---|
| LMArena Instruction Following | 1404 | 1444 |

## Long Context

- DeepSeek-V3.1-Terminus: 43.4 (#97)
- Step 5 Preview: 44.5 (#64)

| Benchmark | DeepSeek-V3.1-Terminus | Step 5 Preview |
|---|---|---|
| LMArena Longer Query | 1421 | 1455 |

## Writing & Preference

- DeepSeek-V3.1-Terminus: 61.0 (#92)
- Step 5 Preview: 62.8 (#71)

| Benchmark | DeepSeek-V3.1-Terminus | Step 5 Preview |
|---|---|---|
| LMArena Text | 1419 | 1442 |
| LMArena Creative Writing | 1403 | 1410 |
| LMArena Multi-Turn | 1411 | 1447 |

## FAQ

### Is DeepSeek-V3.1-Terminus better than Step 5 Preview?

Step 5 Preview is the stronger model overall, scoring 47.9 to 43.1 on the Noometry Index. DeepSeek-V3.1-Terminus costs 3.1× less per token, which makes it the better buy when Step 5 Preview's lead doesn't matter for your workload.

### Which is cheaper, DeepSeek-V3.1-Terminus or Step 5 Preview?

DeepSeek-V3.1-Terminus is cheaper. It lists at $0.27 per million input tokens and $1 per million output tokens; Step 5 Preview lists at $1 and $2.70.

### Is DeepSeek-V3.1-Terminus or Step 5 Preview better for coding?

Step 5 Preview scores higher on coding benchmarks: 51.8 versus 42.0 in the Noometry coding category.

### Which has the bigger context window?

Step 5 Preview does, with 1.02M tokens against 164K.

### How many benchmarks do DeepSeek-V3.1-Terminus and Step 5 Preview share?

12 benchmarks have published results for both models. DeepSeek-V3.1-Terminus has 16 scored results on Noometry and Step 5 Preview has 18.