Model comparison

GPT-5.3 Codex vs GPT-5.4

GPT-5.4 is the stronger model overall, scoring 59.4 to 45.8 on the Noometry Index.

Last verified . 8 shared benchmarks.

GPT-5.3 Codex OpenAI

45.8

Rank #69 Reported

GPT-5.4 OpenAI

59.4

Rank #16 Confirmed

Summary

  • They share 8 benchmarks with published results for both. GPT-5.3 Codex scores higher in 1 category and GPT-5.4 in 1 category; 2 gaps are clear of the uncertainty.
  • The widest gap is in coding, where GPT-5.4 leads 52.6 to 48.6.
  • GPT-5.3 Codex is cheaper at $1.75 / $14 per million input/output tokens, against $2.50 / $15 for GPT-5.4.
  • GPT-5.4 accepts more context: 1.05M tokens versus 400K.

Side by side

GPT-5.3 Codex and GPT-5.4 specifications
GPT-5.3 CodexGPT-5.4
ProviderOpenAIOpenAI
Noometry Index45.859.4
Released2026-02-052026-03-05
WeightsProprietaryProprietary
Context window400K1.05M
Max output128K128K
Input $ / M tokens$1.75$2.50
Output $ / M tokens$14$15
Results tracked868

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Category by category

Coding GPT-5.4 leads

GPT-5.3 Codex: 48.6 (#56), GPT-5.4: 52.6 (#33)

Coding benchmarks
BenchmarkGPT-5.3 CodexGPT-5.4
SWE-bench Verified74.8%76.9%
LMArena WebDev14091465
WeirdML79.3%77.7%
ALE-Bench1,6551,607
DeepSWE—51.8%
SciCode—56.6%
GSO—31.4%
LMArena Coding—1497
MirrorCode—15.6%
AlgoTune—1.85

Agentic & Tool Use GPT-5.3 Codex leads

GPT-5.3 Codex: 48.0 (#9), GPT-5.4: 46.5 (#13)

Agentic & Tool Use benchmarks
BenchmarkGPT-5.3 CodexGPT-5.4
Terminal-Bench78.4%81.8%
METR Time Horizons74.5%74.3%
Vending-Bench 25,9406,144
APEX-Agents—52.4%
τ²-bench Banking—39.4%
DeepResearch Bench—35.1%
PostTrainBench—19%
GBAEval—45.1%
LMArena Search—1197

Reasoning Not comparable

GPT-5.3 Codex: —, GPT-5.4: 61.8 (#19)

Reasoning benchmarks
BenchmarkGPT-5.3 CodexGPT-5.4
Epoch Capabilities Index156.77156.81
ARC-AGI-2—74%
Kagi LLM Benchmark—63.8%
NYT Connections (extended)—91.3%
ARC-AGI-1—93.7%
CritPt—23.4%
Chess Puzzles—44%
EnigmaEval—16%
Thematic Generalization—80%
EBR-Bench—25.4%
LMArena Hard Prompts—1485
Mystery Game Puzzles—37%
DTBench—94.4%
LMCA—52%
ForecastBench—59.5

Math Not comparable

GPT-5.3 Codex: —, GPT-5.4: 73.5 (#19)

Knowledge Not comparable

GPT-5.3 Codex: —, GPT-5.4: 65.3 (#14)

Knowledge benchmarks
BenchmarkGPT-5.3 CodexGPT-5.4
GPQA Diamond—93.3%
Humanity's Last Exam—36.2%
SimpleQA Verified—45.1%
Vectara Hallucination Rate—7%
LMArena Expert—1507

Multimodal Not comparable

GPT-5.3 Codex: —, GPT-5.4: 43.7 (#20)

Multimodal benchmarks
BenchmarkGPT-5.3 CodexGPT-5.4
LMArena Vision—1303
Blueprint-Bench 2—27.1%
Furniture Assembly—37.5%
LMArena Document—1471

Multilingual Not comparable

GPT-5.3 Codex: —, GPT-5.4: 56.2 (#23)

Multilingual benchmarks
BenchmarkGPT-5.3 CodexGPT-5.4
LMArena Non-English—1465
LMArena Chinese—1519
LMArena French—1493
LMArena German—1472
LMArena Japanese—1485
LMArena Korean—1448
LMArena Russian—1480
LMArena Spanish—1454

Instruction Following Not comparable

GPT-5.3 Codex: —, GPT-5.4: 77.1 (#27)

Instruction Following benchmarks
BenchmarkGPT-5.3 CodexGPT-5.4
LMArena Instruction Following—1469

Long Context Not comparable

GPT-5.3 Codex: —, GPT-5.4: 50.3 (#8)

Long Context benchmarks
BenchmarkGPT-5.3 CodexGPT-5.4
CL-bench—27.9%
CL-bench Life—21.7%
LMArena Longer Query—1473

Writing & Preference Not comparable

GPT-5.3 Codex: —, GPT-5.4: 71.9 (#17)

Writing & Preference benchmarks
BenchmarkGPT-5.3 CodexGPT-5.4
LMArena Text—1469
LMArena Creative Writing—1439
EQ-Bench Creative Writing—1840
EQ-Bench 4—1272
LMArena Multi-Turn—1482

Frequently asked questions

Is GPT-5.3 Codex better than GPT-5.4?

GPT-5.4 is the stronger model overall, scoring 59.4 to 45.8 on the Noometry Index.

Which is cheaper, GPT-5.3 Codex or GPT-5.4?

GPT-5.3 Codex is cheaper. It lists at $1.75 per million input tokens and $14 per million output tokens; GPT-5.4 lists at $2.50 and $15.

Is GPT-5.3 Codex or GPT-5.4 better for coding?

GPT-5.4 scores higher on coding benchmarks: 52.6 versus 48.6 in the Noometry coding category.

Which has the bigger context window?

GPT-5.4 does, with 1.05M tokens against 400K.

How many benchmarks do GPT-5.3 Codex and GPT-5.4 share?

8 benchmarks have published results for both models. GPT-5.3 Codex has 8 scored results on Noometry and GPT-5.4 has 68.

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