Noometry

Model comparison

GPT-4 Turbo vs GPT-5.1-Codex

GPT-5.1-Codex is the stronger model overall, scoring 38.2 to 30.3 on the Noometry Index.

Last verified . 1 shared benchmarks.

GPT-4 Turbo OpenAI

30.3

Rank #281 Confirmed

GPT-5.1-Codex OpenAI

38.2

Rank #178 Reported

Summary

  • They share 1 benchmark with published results for both. GPT-4 Turbo scores higher in 0 categories and GPT-5.1-Codex in 2 categories; 2 gaps are clear of the uncertainty.
  • The widest gap is in math, where GPT-5.1-Codex leads 29.3 to 8.6.
  • GPT-5.1-Codex is cheaper at $1.25 / $10 per million input/output tokens, against $10 / $30 for GPT-4 Turbo.
  • GPT-5.1-Codex accepts more context: 400K tokens versus 128K.

Side by side

GPT-4 TurboGPT-5.1-Codex
ProviderOpenAIOpenAI
Noometry Index30.338.2
Released2023-11-062025-11-12
WeightsProprietaryProprietary
Context window128K400K
Max output4K128K
Input $ / M tokens$10$1.25
Output $ / M tokens$30$10
Results tracked366

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Category by category

Coding GPT-5.1-Codex leads

GPT-4 Turbo: 33.4 (#247), GPT-5.1-Codex: 41.7 (#107)

BenchmarkGPT-4 TurboGPT-5.1-Codex
SWE-bench Verified (bash only)—66%
LMArena WebDev—1337
WeirdML18%—
BigCodeBench Instruct48.2%—
LMArena Coding1268—
BigCodeBench Complete58.2%—
ALE-Bench—1,245
HumanEval+86.6%—
MBPP+73.3%—

Agentic & Tool Use Not comparable

GPT-4 Turbo: —, GPT-5.1-Codex: 37.8 (#32)

BenchmarkGPT-4 TurboGPT-5.1-Codex
METR Time Horizons36.7%70.8%
Terminal-Bench—60.4%

Reasoning Not comparable

GPT-4 Turbo: 14.9 (#311), GPT-5.1-Codex: —

BenchmarkGPT-4 TurboGPT-5.1-Codex
SimpleBench25.1%—
Chess Puzzles6%—
LMArena Hard Prompts1251—
DTBench61.6%—
LMCA9.8%—
Epoch Capabilities Index127.25—
ForecastBench59.4—

Math GPT-5.1-Codex leads

GPT-4 Turbo: 8.6 (#316), GPT-5.1-Codex: 29.3 (#218)

BenchmarkGPT-4 TurboGPT-5.1-Codex
FrontierMath (Tiers 1-3)0.7%—
OTIS Mock AIME 2024-20256.7%—
ProofBench—9%
LMArena Math1272—
MATH Level 546.7%—

Knowledge Not comparable

GPT-4 Turbo: 24.3 (#263), GPT-5.1-Codex: —

BenchmarkGPT-4 TurboGPT-5.1-Codex
GPQA Diamond46.6%—
Confabulations28.4%—
LMArena Expert1223—
MMLU81.3%—

Multimodal Not comparable

GPT-4 Turbo: 30.0 (#104), GPT-5.1-Codex: —

BenchmarkGPT-4 TurboGPT-5.1-Codex
LMArena Vision1090—

Multilingual Not comparable

GPT-4 Turbo: 40.7 (#211), GPT-5.1-Codex: —

BenchmarkGPT-4 TurboGPT-5.1-Codex
LMArena Non-English1245—
LMArena Chinese1242—
LMArena French1275—
LMArena German1259—
LMArena Japanese1194—
LMArena Korean1187—
LMArena Russian1259—
LMArena Spanish1260—

Instruction Following Not comparable

GPT-4 Turbo: 66.0 (#211), GPT-5.1-Codex: —

BenchmarkGPT-4 TurboGPT-5.1-Codex
LMArena Instruction Following1250—

Long Context Not comparable

GPT-4 Turbo: 38.0 (#200), GPT-5.1-Codex: —

BenchmarkGPT-4 TurboGPT-5.1-Codex
LMArena Longer Query1254—

Writing & Preference Not comparable

GPT-4 Turbo: 47.9 (#201), GPT-5.1-Codex: —

BenchmarkGPT-4 TurboGPT-5.1-Codex
LMArena Text1272—
LMArena Creative Writing1269—
LMArena Multi-Turn1267—

Frequently asked questions

Is GPT-4 Turbo better than GPT-5.1-Codex?

GPT-5.1-Codex is the stronger model overall, scoring 38.2 to 30.3 on the Noometry Index.

Which is cheaper, GPT-4 Turbo or GPT-5.1-Codex?

GPT-5.1-Codex is cheaper. It lists at $1.25 per million input tokens and $10 per million output tokens; GPT-4 Turbo lists at $10 and $30.

Is GPT-4 Turbo or GPT-5.1-Codex better for coding?

GPT-5.1-Codex scores higher on coding benchmarks: 41.7 versus 33.4 in the Noometry coding category.

Which has the bigger context window?

GPT-5.1-Codex does, with 400K tokens against 128K.

How many benchmarks do GPT-4 Turbo and GPT-5.1-Codex share?

1 benchmark has published results for both models. GPT-4 Turbo has 36 scored results on Noometry and GPT-5.1-Codex has 6.

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