# GPT-5.1-Codex vs MiMo-V2.6-Flash

> MiMo-V2.6-Flash is the stronger model overall, scoring 48.5 to 38.6 on the Noometry Index.

- Canonical page: https://noometry.com/compare/gpt-5-1-codex-vs-mimo-v2-6-flash
- Last updated: 2026-10-12
- Shared benchmarks: 2

## Summary

- They share 2 benchmarks with published results for both. GPT-5.1-Codex scores higher in 0 categories and MiMo-V2.6-Flash in 2 categories; 2 gaps are clear of the uncertainty.
- The widest gap is in math, where MiMo-V2.6-Flash leads 51.9 to 30.3.
- The biggest single-benchmark swing is ProofBench: 9% for GPT-5.1-Codex and 63% for MiMo-V2.6-Flash.
- MiMo-V2.6-Flash is cheaper at $0.14 / $0.28 per million input/output tokens, against $1.25 / $10 for GPT-5.1-Codex.
- MiMo-V2.6-Flash accepts more context: 1.05M tokens versus 400K.
- MiMo-V2.6-Flash has downloadable open weights; the other is API-only.

## Snapshot

| | GPT-5.1-Codex | MiMo-V2.6-Flash |
|---|---|---|
| Provider | OpenAI | Xiaomi |
| Noometry Index | 38.6 | 48.5 |
| Rank | 186 | 55 |
| Context | 400K | 1.05M |
| Input $/M | $1.25 | $0.14 |
| Output $/M | $10 | $0.28 |
| Weights | Proprietary | Open |

## Coding

- GPT-5.1-Codex: 41.9 (#116)
- MiMo-V2.6-Flash: 53.4 (#30)

| Benchmark | GPT-5.1-Codex | MiMo-V2.6-Flash |
|---|---|---|
| LMArena WebDev | 1337 | 1637 |
| SWE-bench Verified (bash only) | 66% | — |
| SciCode | — | 51.3% |
| LMArena Coding | — | 1504 |
| ALE-Bench | 1,245 | — |

## Agentic & Tool Use

- GPT-5.1-Codex: 38.0 (#33)
- MiMo-V2.6-Flash: —

| Benchmark | GPT-5.1-Codex | MiMo-V2.6-Flash |
|---|---|---|
| Terminal-Bench | 60.4% | — |
| METR Time Horizons | 70.8% | — |

## Reasoning

- GPT-5.1-Codex: —
- MiMo-V2.6-Flash: 36.5 (#66)

| Benchmark | GPT-5.1-Codex | MiMo-V2.6-Flash |
|---|---|---|
| CritPt | — | 12% |
| LMArena Hard Prompts | — | 1482 |

## Math

- GPT-5.1-Codex: 30.3 (#235)
- MiMo-V2.6-Flash: 51.9 (#52)

| Benchmark | GPT-5.1-Codex | MiMo-V2.6-Flash |
|---|---|---|
| ProofBench | 9% | 63% |
| LMArena Math | — | 1468 |

## Knowledge

- GPT-5.1-Codex: —
- MiMo-V2.6-Flash: 42.2 (#99)

| Benchmark | GPT-5.1-Codex | MiMo-V2.6-Flash |
|---|---|---|
| LMArena Expert | — | 1501 |

## Multimodal

- GPT-5.1-Codex: —
- MiMo-V2.6-Flash: 40.5 (#47)

| Benchmark | GPT-5.1-Codex | MiMo-V2.6-Flash |
|---|---|---|
| LMArena Vision | — | 1259 |

## Multilingual

- GPT-5.1-Codex: —
- MiMo-V2.6-Flash: 54.0 (#51)

| Benchmark | GPT-5.1-Codex | MiMo-V2.6-Flash |
|---|---|---|
| LMArena Non-English | — | 1434 |
| LMArena Chinese | — | 1511 |
| LMArena French | — | 1475 |
| LMArena Russian | — | 1409 |
| LMArena Spanish | — | 1456 |

## Instruction Following

- GPT-5.1-Codex: —
- MiMo-V2.6-Flash: 76.8 (#35)

| Benchmark | GPT-5.1-Codex | MiMo-V2.6-Flash |
|---|---|---|
| LMArena Instruction Following | — | 1463 |

## Long Context

- GPT-5.1-Codex: —
- MiMo-V2.6-Flash: 44.8 (#57)

| Benchmark | GPT-5.1-Codex | MiMo-V2.6-Flash |
|---|---|---|
| LMArena Longer Query | — | 1463 |

## Writing & Preference

- GPT-5.1-Codex: —
- MiMo-V2.6-Flash: 63.1 (#67)

| Benchmark | GPT-5.1-Codex | MiMo-V2.6-Flash |
|---|---|---|
| LMArena Text | — | 1455 |
| LMArena Creative Writing | — | 1400 |
| LMArena Multi-Turn | — | 1451 |

## FAQ

### Is GPT-5.1-Codex better than MiMo-V2.6-Flash?

MiMo-V2.6-Flash is the stronger model overall, scoring 48.5 to 38.6 on the Noometry Index.

### Which is cheaper, GPT-5.1-Codex or MiMo-V2.6-Flash?

MiMo-V2.6-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-V2.6-Flash better for coding?

MiMo-V2.6-Flash scores higher on coding benchmarks: 53.4 versus 41.9 in the Noometry coding category.

### Which has the bigger context window?

MiMo-V2.6-Flash does, with 1.05M tokens against 400K.

### How many benchmarks do GPT-5.1-Codex and MiMo-V2.6-Flash share?

2 benchmarks have published results for both models. GPT-5.1-Codex has 6 scored results on Noometry and MiMo-V2.6-Flash has 19.