# GPT-5.1-Codex vs MiMo-V2-Flash

> MiMo-V2-Flash is the stronger model overall, scoring 41.3 to 38.6 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gpt-5-1-codex-vs-mimo-v2-flash
- Last updated: 2026-10-11
- Shared benchmarks: 2

## Summary

- They share 2 benchmarks with published results for both. GPT-5.1-Codex scores higher in 1 category and MiMo-V2-Flash in 1 category; 2 gaps are clear of the uncertainty.
- The widest gap is in math, where MiMo-V2-Flash leads 38.3 to 30.3.
- MiMo-V2-Flash is cheaper at $0.14 / $0.28 per million input/output tokens, against $1.25 / $10 for GPT-5.1-Codex.
- GPT-5.1-Codex accepts more context: 400K tokens versus 262K.
- MiMo-V2-Flash has downloadable open weights; the other is API-only.

## Snapshot

| | GPT-5.1-Codex | MiMo-V2-Flash |
|---|---|---|
| Provider | OpenAI | Xiaomi |
| Noometry Index | 38.6 | 41.3 |
| Rank | 186 | 138 |
| Context | 400K | 262K |
| Input $/M | $1.25 | $0.14 |
| Output $/M | $10 | $0.28 |
| Weights | Proprietary | Open |

## Coding

- GPT-5.1-Codex: 41.9 (#116)
- MiMo-V2-Flash: 36.1 (#211)

| Benchmark | GPT-5.1-Codex | MiMo-V2-Flash |
|---|---|---|
| LMArena WebDev | 1337 | 1330 |
| ALE-Bench | 1,245 | 737.95 |
| SWE-bench Verified (bash only) | 66% | — |
| SciCode | — | 25.9% |
| LMArena Coding | — | 1443 |

## Agentic & Tool Use

- GPT-5.1-Codex: 38.0 (#33)
- MiMo-V2-Flash: —

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

## Reasoning

- GPT-5.1-Codex: —
- MiMo-V2-Flash: 24.9 (#157)

| Benchmark | GPT-5.1-Codex | MiMo-V2-Flash |
|---|---|---|
| CritPt | — | 0% |
| LMArena Hard Prompts | — | 1420 |

## Math

- GPT-5.1-Codex: 30.3 (#235)
- MiMo-V2-Flash: 38.3 (#139)

| Benchmark | GPT-5.1-Codex | MiMo-V2-Flash |
|---|---|---|
| ProofBench | 9% | — |
| LMArena Math | — | 1396 |

## Knowledge

- GPT-5.1-Codex: —
- MiMo-V2-Flash: 39.7 (#131)

| Benchmark | GPT-5.1-Codex | MiMo-V2-Flash |
|---|---|---|
| LMArena Expert | — | 1425 |

## Multilingual

- GPT-5.1-Codex: —
- MiMo-V2-Flash: 51.0 (#113)

| Benchmark | GPT-5.1-Codex | MiMo-V2-Flash |
|---|---|---|
| LMArena Non-English | — | 1392 |
| LMArena Chinese | — | 1462 |
| LMArena French | — | 1429 |
| LMArena German | — | 1395 |
| LMArena Japanese | — | 1325 |
| LMArena Korean | — | 1358 |
| LMArena Russian | — | 1387 |
| LMArena Spanish | — | 1420 |

## Instruction Following

- GPT-5.1-Codex: —
- MiMo-V2-Flash: 73.5 (#120)

| Benchmark | GPT-5.1-Codex | MiMo-V2-Flash |
|---|---|---|
| LMArena Instruction Following | — | 1392 |

## Long Context

- GPT-5.1-Codex: —
- MiMo-V2-Flash: 43.0 (#110)

| Benchmark | GPT-5.1-Codex | MiMo-V2-Flash |
|---|---|---|
| LMArena Longer Query | — | 1409 |

## Writing & Preference

- GPT-5.1-Codex: —
- MiMo-V2-Flash: 59.7 (#106)

| Benchmark | GPT-5.1-Codex | MiMo-V2-Flash |
|---|---|---|
| LMArena Text | — | 1411 |
| LMArena Creative Writing | — | 1375 |
| LMArena Multi-Turn | — | 1404 |

## FAQ

### Is GPT-5.1-Codex better than MiMo-V2-Flash?

MiMo-V2-Flash is the stronger model overall, scoring 41.3 to 38.6 on the Noometry Index.

### Which is cheaper, GPT-5.1-Codex or MiMo-V2-Flash?

MiMo-V2-Flash is cheaper. It lists at $0.14 per million input tokens and $0.28 per million output tokens; GPT-5.1-Codex lists at $1.25 and $10.

### Is GPT-5.1-Codex or MiMo-V2-Flash better for coding?

GPT-5.1-Codex scores higher on coding benchmarks: 41.9 versus 36.1 in the Noometry coding category.

### Which has the bigger context window?

GPT-5.1-Codex does, with 400K tokens against 262K.

### How many benchmarks do GPT-5.1-Codex and MiMo-V2-Flash share?

2 benchmarks have published results for both models. GPT-5.1-Codex has 6 scored results on Noometry and MiMo-V2-Flash has 21.