Model comparison

GPT-5.1-Codex vs o1-mini

GPT-5.1-Codex is the stronger model overall, scoring 38.6 to 34.0 on the Noometry Index.

Last verified . 0 shared benchmarks.

GPT-5.1-Codex OpenAI

38.6

Rank #186 Reported

o1-mini OpenAI

34.0

Rank #235 Confirmed

Summary

  • The widest gap is in agentic & tool use, where GPT-5.1-Codex leads 38.0 to 24.6.

Side by side

GPT-5.1-Codex and o1-mini specifications
GPT-5.1-Codexo1-mini
ProviderOpenAIOpenAI
Noometry Index38.634.0
Released2025-11-122024-09-12
WeightsProprietaryProprietary
Context window400K—
Max output128K—
Input $ / M tokens$1.25—
Output $ / M tokens$10—
Results tracked639

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Category by category

Coding GPT-5.1-Codex leads

GPT-5.1-Codex: 41.9 (#116), o1-mini: 35.5 (#224)

Coding benchmarks
BenchmarkGPT-5.1-Codexo1-mini
SWE-bench Verified (bash only)66%—
Aider Polyglot—32.9%
LMArena WebDev1337—
WeirdML—36.3%
LiveBench Coding—48%
LMArena Coding—1362
ALE-Bench1,245—
HumanEval+—89%
MBPP+—78.8%

Agentic & Tool Use GPT-5.1-Codex leads

GPT-5.1-Codex: 38.0 (#33), o1-mini: 24.6 (#118)

Agentic & Tool Use benchmarks
BenchmarkGPT-5.1-Codexo1-mini
Terminal-Bench60.4%—
Cybench—10%
METR Time Horizons70.8%—

Reasoning Not comparable

GPT-5.1-Codex: —, o1-mini: 8.8 (#346)

Reasoning benchmarks
BenchmarkGPT-5.1-Codexo1-mini
ARC-AGI-2—0.8%
SimpleBench—18.1%
ARC-AGI-1—14%
LiveBench Reasoning—72.3%
LMArena Hard Prompts—1333
LiveBench Data Analysis—57.9%
Epoch Capabilities Index—135.82
LiveBench—57.8%

Math o1-mini leads

GPT-5.1-Codex: 30.3 (#235), o1-mini: 35.4 (#186)

Math benchmarks
BenchmarkGPT-5.1-Codexo1-mini
OTIS Mock AIME 2024-2025—46.9%
ProofBench9%—
LiveBench Math—62%
LMArena Math—1358
MATH Level 5—89.2%
FrontierMath (Feb 2025 set)—1.7%

Knowledge Not comparable

GPT-5.1-Codex: —, o1-mini: 34.9 (#192)

Knowledge benchmarks
BenchmarkGPT-5.1-Codexo1-mini
GPQA Diamond—62.4%
Confabulations—18.6%
LMArena Expert—1316

Multilingual Not comparable

GPT-5.1-Codex: —, o1-mini: 43.6 (#182)

Multilingual benchmarks
BenchmarkGPT-5.1-Codexo1-mini
LMArena Non-English—1289
LMArena Chinese—1314
LMArena French—1293
LMArena German—1278
LMArena Japanese—1245
LMArena Korean—1223
LMArena Russian—1283
LMArena Spanish—1303

Instruction Following Not comparable

GPT-5.1-Codex: —, o1-mini: 66.7 (#206)

Instruction Following benchmarks
BenchmarkGPT-5.1-Codexo1-mini
LiveBench Instruction Following—65.4%
LMArena Instruction Following—1304

Long Context Not comparable

GPT-5.1-Codex: —, o1-mini: 40.1 (#161)

Long Context benchmarks
BenchmarkGPT-5.1-Codexo1-mini
LMArena Longer Query—1320

Writing & Preference Not comparable

GPT-5.1-Codex: —, o1-mini: 48.4 (#202)

Writing & Preference benchmarks
BenchmarkGPT-5.1-Codexo1-mini
LMArena Text—1317
LMArena Creative Writing—1244
Short-Story Creative Writing—64.9%
LMArena Multi-Turn—1314
LiveBench Language—40.9%

Frequently asked questions

Is GPT-5.1-Codex better than o1-mini?

GPT-5.1-Codex is the stronger model overall, scoring 38.6 to 34.0 on the Noometry Index.

Is GPT-5.1-Codex or o1-mini better for coding?

GPT-5.1-Codex scores higher on coding benchmarks: 41.9 versus 35.5 in the Noometry coding category.

How many benchmarks do GPT-5.1-Codex and o1-mini share?

0 benchmarks have published results for both models. GPT-5.1-Codex has 6 scored results on Noometry and o1-mini has 39.

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