Model comparison

GPT-5.2 Codex vs Step 2 16k Exp 202412

GPT-5.2 Codex is the stronger model overall, scoring 42.2 to 38.6 on the Noometry Index.

Last verified . 0 shared benchmarks.

GPT-5.2 Codex OpenAI

42.2

Rank #107 Reported

Step 2 16k Exp 202412 StepFun

38.6

Rank #173 Confirmed

Summary

  • The widest gap is in coding, where GPT-5.2 Codex leads 45.4 to 37.9.

Side by side

GPT-5.2 Codex and Step 2 16k Exp 202412 specifications
GPT-5.2 CodexStep 2 16k Exp 202412
ProviderOpenAIStepFun
Noometry Index42.238.6
Released2025-12-18—
WeightsProprietaryProprietary
Context window400K—
Max output128K—
Input $ / M tokens$1.75—
Output $ / M tokens$14—
Results tracked512

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Category by category

Coding GPT-5.2 Codex leads

GPT-5.2 Codex: 45.4 (#66), Step 2 16k Exp 202412: 37.9 (#170)

Coding benchmarks
BenchmarkGPT-5.2 CodexStep 2 16k Exp 202412
SWE-bench Verified (bash only)72.8%—
LMArena WebDev1339—
SWE-bench Multilingual66.3%—
LMArena Coding—1316
ALE-Bench1,300—

Agentic & Tool Use Not comparable

GPT-5.2 Codex: 40.7 (#20), Step 2 16k Exp 202412: —

Agentic & Tool Use benchmarks
BenchmarkGPT-5.2 CodexStep 2 16k Exp 202412
Terminal-Bench66.5%—

Reasoning Not comparable

GPT-5.2 Codex: —, Step 2 16k Exp 202412: 24.8 (#140)

Reasoning benchmarks
BenchmarkGPT-5.2 CodexStep 2 16k Exp 202412
LMArena Hard Prompts—1299

Math Not comparable

GPT-5.2 Codex: —, Step 2 16k Exp 202412: 33.6 (#171)

Math benchmarks
BenchmarkGPT-5.2 CodexStep 2 16k Exp 202412
LMArena Math—1305

Knowledge Not comparable

GPT-5.2 Codex: —, Step 2 16k Exp 202412: 34.6 (#187)

Knowledge benchmarks
BenchmarkGPT-5.2 CodexStep 2 16k Exp 202412
LMArena Expert—1279

Multilingual Not comparable

GPT-5.2 Codex: —, Step 2 16k Exp 202412: 43.9 (#176)

Multilingual benchmarks
BenchmarkGPT-5.2 CodexStep 2 16k Exp 202412
LMArena Non-English—1290
LMArena Chinese—1331
LMArena Russian—1324

Instruction Following Not comparable

GPT-5.2 Codex: —, Step 2 16k Exp 202412: 68.1 (#187)

Instruction Following benchmarks
BenchmarkGPT-5.2 CodexStep 2 16k Exp 202412
LMArena Instruction Following—1287

Long Context Not comparable

GPT-5.2 Codex: —, Step 2 16k Exp 202412: 39.7 (#165)

Long Context benchmarks
BenchmarkGPT-5.2 CodexStep 2 16k Exp 202412
LMArena Longer Query—1307

Writing & Preference Not comparable

GPT-5.2 Codex: —, Step 2 16k Exp 202412: 52.5 (#168)

Writing & Preference benchmarks
BenchmarkGPT-5.2 CodexStep 2 16k Exp 202412
LMArena Text—1321
LMArena Creative Writing—1328
LMArena Multi-Turn—1292

Frequently asked questions

Is GPT-5.2 Codex better than Step 2 16k Exp 202412?

GPT-5.2 Codex is the stronger model overall, scoring 42.2 to 38.6 on the Noometry Index.

Is GPT-5.2 Codex or Step 2 16k Exp 202412 better for coding?

GPT-5.2 Codex scores higher on coding benchmarks: 45.4 versus 37.9 in the Noometry coding category.

How many benchmarks do GPT-5.2 Codex and Step 2 16k Exp 202412 share?

0 benchmarks have published results for both models. GPT-5.2 Codex has 5 scored results on Noometry and Step 2 16k Exp 202412 has 12.

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