Model comparison

GPT-5.1-Codex vs Kimi K2 Thinking Turbo

Kimi K2 Thinking Turbo is the stronger model overall, scoring 45.8 to 38.6 on the Noometry Index.

Last verified . 1 shared benchmarks.

GPT-5.1-Codex OpenAI

38.6

Rank #186 Reported

Kimi K2 Thinking Turbo Moonshot AI

45.8

Rank #70 Confirmed

Summary

  • They share 1 benchmark with published results for both. GPT-5.1-Codex scores higher in 1 category and Kimi K2 Thinking Turbo in 1 category; 2 gaps are clear of the uncertainty.
  • The widest gap is in math, where Kimi K2 Thinking Turbo leads 47.4 to 30.3.
  • Kimi K2 Thinking Turbo has downloadable open weights; the other is API-only.

Side by side

GPT-5.1-Codex and Kimi K2 Thinking Turbo specifications
GPT-5.1-CodexKimi K2 Thinking Turbo
ProviderOpenAIMoonshot AI
Noometry Index38.645.8
Released2025-11-122025-11-06
WeightsProprietaryOpen
Context window400K—
Max output128K—
Input $ / M tokens$1.25—
Output $ / M tokens$10—
Results tracked621

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Category by category

Coding GPT-5.1-Codex leads

GPT-5.1-Codex: 41.9 (#116), Kimi K2 Thinking Turbo: 38.4 (#178)

Coding benchmarks
BenchmarkGPT-5.1-CodexKimi K2 Thinking Turbo
LMArena WebDev13371322
SWE-bench Verified (bash only)66%—
LMArena Coding—1454
ALE-Bench1,245—

Agentic & Tool Use Not comparable

GPT-5.1-Codex: 38.0 (#33), Kimi K2 Thinking Turbo: —

Agentic & Tool Use benchmarks
BenchmarkGPT-5.1-CodexKimi K2 Thinking Turbo
Terminal-Bench60.4%—
METR Time Horizons70.8%—

Reasoning Not comparable

GPT-5.1-Codex: —, Kimi K2 Thinking Turbo: 32.5 (#75)

Reasoning benchmarks
BenchmarkGPT-5.1-CodexKimi K2 Thinking Turbo
Chess Puzzles—20%
LMArena Hard Prompts—1428

Math Kimi K2 Thinking Turbo leads

GPT-5.1-Codex: 30.3 (#235), Kimi K2 Thinking Turbo: 47.4 (#68)

Math benchmarks
BenchmarkGPT-5.1-CodexKimi K2 Thinking Turbo
OTIS Mock AIME 2024-2025—83.1%
ProofBench9%—
LMArena Math—1429

Knowledge Not comparable

GPT-5.1-Codex: —, Kimi K2 Thinking Turbo: 50.9 (#69)

Knowledge benchmarks
BenchmarkGPT-5.1-CodexKimi K2 Thinking Turbo
GPQA Diamond—84.2%
LMArena Expert—1439

Multilingual Not comparable

GPT-5.1-Codex: —, Kimi K2 Thinking Turbo: 51.4 (#109)

Multilingual benchmarks
BenchmarkGPT-5.1-CodexKimi K2 Thinking Turbo
LMArena Non-English—1398
LMArena Chinese—1456
LMArena French—1425
LMArena German—1390
LMArena Japanese—1357
LMArena Korean—1330
LMArena Russian—1391
LMArena Spanish—1406

Instruction Following Not comparable

GPT-5.1-Codex: —, Kimi K2 Thinking Turbo: 74.0 (#109)

Instruction Following benchmarks
BenchmarkGPT-5.1-CodexKimi K2 Thinking Turbo
LMArena Instruction Following—1403

Long Context Not comparable

GPT-5.1-Codex: —, Kimi K2 Thinking Turbo: 43.2 (#102)

Long Context benchmarks
BenchmarkGPT-5.1-CodexKimi K2 Thinking Turbo
LMArena Longer Query—1415

Writing & Preference Not comparable

GPT-5.1-Codex: —, Kimi K2 Thinking Turbo: 60.0 (#104)

Writing & Preference benchmarks
BenchmarkGPT-5.1-CodexKimi K2 Thinking Turbo
LMArena Text—1415
LMArena Creative Writing—1374
LMArena Multi-Turn—1414

Frequently asked questions

Is GPT-5.1-Codex better than Kimi K2 Thinking Turbo?

Kimi K2 Thinking Turbo is the stronger model overall, scoring 45.8 to 38.6 on the Noometry Index.

Is GPT-5.1-Codex or Kimi K2 Thinking Turbo better for coding?

GPT-5.1-Codex scores higher on coding benchmarks: 41.9 versus 38.4 in the Noometry coding category.

How many benchmarks do GPT-5.1-Codex and Kimi K2 Thinking Turbo share?

1 benchmark has published results for both models. GPT-5.1-Codex has 6 scored results on Noometry and Kimi K2 Thinking Turbo has 21.

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