Model comparison

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.

Last verified . 3 shared benchmarks.

GPT-5.1-Codex OpenAI

38.6

Rank #186 Reported

MiMo-V2.5-Pro Xiaomi

45.2

Rank #74 Confirmed

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.

Side by side

GPT-5.1-Codex and MiMo-V2.5-Pro specifications
GPT-5.1-CodexMiMo-V2.5-Pro
ProviderOpenAIXiaomi
Noometry Index38.645.2
Released2025-11-122026-04-22
WeightsProprietaryOpen
Context window400K1.05M
Max output128K131K
Input $ / M tokens$1.25$0.43
Output $ / M tokens$10$0.87
Results tracked627

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Category by category

Coding MiMo-V2.5-Pro leads

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

Coding benchmarks
BenchmarkGPT-5.1-CodexMiMo-V2.5-Pro
LMArena WebDev13371479
ALE-Bench1,245899.8
SWE-bench Verified (bash only)66%—
SciCode—50.2%
LMArena Coding—1503

Agentic & Tool Use Not comparable

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

Agentic & Tool Use benchmarks
BenchmarkGPT-5.1-CodexMiMo-V2.5-Pro
Terminal-Bench60.4%—
METR Time Horizons70.8%—

Reasoning Not comparable

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

Reasoning benchmarks
BenchmarkGPT-5.1-CodexMiMo-V2.5-Pro
NYT Connections (extended)—34.4%
CritPt—4%
LMArena Hard Prompts—1488
DTBench—84.5%
LMCA—29.5%

Math MiMo-V2.5-Pro leads

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

Math benchmarks
BenchmarkGPT-5.1-CodexMiMo-V2.5-Pro
ProofBench9%22%
LMArena Math—1481

Knowledge Not comparable

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

Knowledge benchmarks
BenchmarkGPT-5.1-CodexMiMo-V2.5-Pro
LMArena Expert—1503

Multilingual Not comparable

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

Multilingual benchmarks
BenchmarkGPT-5.1-CodexMiMo-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 Not comparable

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

Instruction Following benchmarks
BenchmarkGPT-5.1-CodexMiMo-V2.5-Pro
LMArena Instruction Following—1477

Long Context Not comparable

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

Long Context benchmarks
BenchmarkGPT-5.1-CodexMiMo-V2.5-Pro
LMArena Longer Query—1483

Writing & Preference Not comparable

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

Writing & Preference benchmarks
BenchmarkGPT-5.1-CodexMiMo-V2.5-Pro
LMArena Text—1465
LMArena Creative Writing—1440
EQ-Bench Creative Writing—1493
EQ-Bench 4—1208
LMArena Multi-Turn—1477

Frequently asked questions

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.

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