# GPT-5.1-Codex vs MiMo-V2.5-Pro

> MiMo-V2.5-Pro is the stronger model overall, scoring 45.2 to 38.6 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gpt-5-1-codex-vs-mimo-v2-5-pro
- Last updated: 2026-10-10
- Shared benchmarks: 3

## Summary

- They share 3 benchmarks with published results for both. GPT-5.1-Codex scores higher in 0 categories and MiMo-V2.5-Pro in 2 categories; 2 gaps are clear of the uncertainty.
- The widest gap is in math, where MiMo-V2.5-Pro leads 40.0 to 30.3.
- The biggest single-benchmark swing is ProofBench: 9% for GPT-5.1-Codex and 22% for MiMo-V2.5-Pro.
- MiMo-V2.5-Pro is cheaper at $0.43 / $0.87 per million input/output tokens, against $1.25 / $10 for GPT-5.1-Codex.
- MiMo-V2.5-Pro accepts more context: 1.05M tokens versus 400K.
- MiMo-V2.5-Pro has downloadable open weights; the other is API-only.

## Snapshot

| | GPT-5.1-Codex | MiMo-V2.5-Pro |
|---|---|---|
| Provider | OpenAI | Xiaomi |
| Noometry Index | 38.6 | 45.2 |
| Rank | 186 | 74 |
| Context | 400K | 1.05M |
| Input $/M | $1.25 | $0.43 |
| Output $/M | $10 | $0.87 |
| Weights | Proprietary | Open |

## Coding

- GPT-5.1-Codex: 41.9 (#116)
- MiMo-V2.5-Pro: 47.4 (#60)

| Benchmark | GPT-5.1-Codex | MiMo-V2.5-Pro |
|---|---|---|
| LMArena WebDev | 1337 | 1479 |
| ALE-Bench | 1,245 | 899.8 |
| SWE-bench Verified (bash only) | 66% | — |
| SciCode | — | 50.2% |
| LMArena Coding | — | 1503 |

## Agentic & Tool Use

- GPT-5.1-Codex: 38.0 (#33)
- MiMo-V2.5-Pro: —

| Benchmark | GPT-5.1-Codex | MiMo-V2.5-Pro |
|---|---|---|
| Terminal-Bench | 60.4% | — |
| METR Time Horizons | 70.8% | — |

## Reasoning

- GPT-5.1-Codex: —
- MiMo-V2.5-Pro: 26.8 (#130)

| Benchmark | GPT-5.1-Codex | MiMo-V2.5-Pro |
|---|---|---|
| NYT Connections (extended) | — | 34.4% |
| CritPt | — | 4% |
| LMArena Hard Prompts | — | 1488 |
| DTBench | — | 84.5% |
| LMCA | — | 29.5% |

## Math

- GPT-5.1-Codex: 30.3 (#235)
- MiMo-V2.5-Pro: 40.0 (#96)

| Benchmark | GPT-5.1-Codex | MiMo-V2.5-Pro |
|---|---|---|
| ProofBench | 9% | 22% |
| LMArena Math | — | 1481 |

## Knowledge

- GPT-5.1-Codex: —
- MiMo-V2.5-Pro: 42.2 (#98)

| Benchmark | GPT-5.1-Codex | MiMo-V2.5-Pro |
|---|---|---|
| LMArena Expert | — | 1503 |

## Multilingual

- GPT-5.1-Codex: —
- MiMo-V2.5-Pro: 55.1 (#34)

| Benchmark | GPT-5.1-Codex | MiMo-V2.5-Pro |
|---|---|---|
| LMArena Non-English | — | 1449 |
| LMArena Chinese | — | 1507 |
| LMArena French | — | 1488 |
| LMArena German | — | 1458 |
| LMArena Japanese | — | 1412 |
| LMArena Korean | — | 1437 |
| LMArena Russian | — | 1450 |
| LMArena Spanish | — | 1471 |

## Instruction Following

- GPT-5.1-Codex: —
- MiMo-V2.5-Pro: 77.5 (#21)

| Benchmark | GPT-5.1-Codex | MiMo-V2.5-Pro |
|---|---|---|
| LMArena Instruction Following | — | 1477 |

## Long Context

- GPT-5.1-Codex: —
- MiMo-V2.5-Pro: 45.4 (#37)

| Benchmark | GPT-5.1-Codex | MiMo-V2.5-Pro |
|---|---|---|
| LMArena Longer Query | — | 1483 |

## Writing & Preference

- GPT-5.1-Codex: —
- MiMo-V2.5-Pro: 65.3 (#49)

| Benchmark | GPT-5.1-Codex | MiMo-V2.5-Pro |
|---|---|---|
| LMArena Text | — | 1465 |
| LMArena Creative Writing | — | 1440 |
| EQ-Bench Creative Writing | — | 1493 |
| EQ-Bench 4 | — | 1208 |
| LMArena Multi-Turn | — | 1477 |

## FAQ

### Is GPT-5.1-Codex better than MiMo-V2.5-Pro?

MiMo-V2.5-Pro is the stronger model overall, scoring 45.2 to 38.6 on the Noometry Index.

### Which is cheaper, GPT-5.1-Codex or MiMo-V2.5-Pro?

MiMo-V2.5-Pro is cheaper. It lists at $0.43 per million input tokens and $0.87 per million output tokens; GPT-5.1-Codex lists at $1.25 and $10.

### Is GPT-5.1-Codex or MiMo-V2.5-Pro better for coding?

MiMo-V2.5-Pro scores higher on coding benchmarks: 47.4 versus 41.9 in the Noometry coding category.

### Which has the bigger context window?

MiMo-V2.5-Pro does, with 1.05M tokens against 400K.

### How many benchmarks do GPT-5.1-Codex and MiMo-V2.5-Pro share?

3 benchmarks have published results for both models. GPT-5.1-Codex has 6 scored results on Noometry and MiMo-V2.5-Pro has 27.