Model comparison

Claude Opus 4 vs GPT-5.2 Codex

Claude Opus 4 and GPT-5.2 Codex score almost the same on the Noometry Index (43.1 vs 42.6), so choose on price, context window or the category you care about most.

Last verified . 1 shared benchmarks.

Claude Opus 4 Anthropic

43.1

Rank #100 Confirmed

GPT-5.2 Codex OpenAI

42.6

Rank #111 Reported

Summary

  • They share 1 benchmark with published results for both. Claude Opus 4 scores higher in 1 category and GPT-5.2 Codex in 1 category; 2 gaps are clear of the uncertainty.
  • The widest gap is in agentic & tool use, where GPT-5.2 Codex leads 41.0 to 34.8.
  • The biggest single-benchmark swing is SWE-bench Verified (bash only): 67.6% for Claude Opus 4 and 72.8% for GPT-5.2 Codex.
  • GPT-5.2 Codex is cheaper at $1.75 / $14 per million input/output tokens, against $15 / $75 for Claude Opus 4.
  • GPT-5.2 Codex accepts more context: 400K tokens versus 200K.

Side by side

Claude Opus 4 and GPT-5.2 Codex specifications
Claude Opus 4GPT-5.2 Codex
ProviderAnthropicOpenAI
Noometry Index43.142.6
Released2025-05-222025-12-18
WeightsProprietaryProprietary
Context window200K400K
Max output32K128K
Input $ / M tokens$15$1.75
Output $ / M tokens$75$14
Results tracked565

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Category by category

Coding Claude Opus 4 leads

Claude Opus 4: 47.2 (#62), GPT-5.2 Codex: 45.5 (#71)

Coding benchmarks
BenchmarkClaude Opus 4GPT-5.2 Codex
SWE-bench Verified (bash only)67.6%72.8%
SWE-bench Verified70.7%—
Aider Polyglot72%—
LMArena WebDev—1339
SWE-bench Multilingual—66.3%
GSO6.9%—
WeirdML43.7%—
LMArena Coding1442—
ALE-Bench—1,300
AlgoTune1.33—

Agentic & Tool Use GPT-5.2 Codex leads

Claude Opus 4: 34.8 (#42), GPT-5.2 Codex: 41.0 (#22)

Agentic & Tool Use benchmarks
BenchmarkClaude Opus 4GPT-5.2 Codex
Terminal-Bench—66.5%
Cybench38%—
DeepResearch Bench46.8%—
LMArena Search1127—
METR Time Horizons63.9%—

Reasoning Not comparable

Claude Opus 4: 27.3 (#121), GPT-5.2 Codex: —

Reasoning benchmarks
BenchmarkClaude Opus 4GPT-5.2 Codex
ARC-AGI-28.6%—
SimpleBench58.8%—
Kagi LLM Benchmark74.3%—
ARC-AGI-135.7%—
CritPt0.3%—
EnigmaEval5.6%—
LMArena Hard Prompts1399—
DTBench81.6%—
LMCA37.4%—
Epoch Capabilities Index142.67—
ForecastBench61.1—

Math Not comparable

Claude Opus 4: 42.0 (#86), GPT-5.2 Codex: —

Math benchmarks
BenchmarkClaude Opus 4GPT-5.2 Codex
OTIS Mock AIME 2024-202564.4%—
Omni-MATH61.6%—
LMArena Math1390—
MATH Level 585%—
FrontierMath (Feb 2025 set)4.5%—
FrontierMath Tier 4 (v1)4.2%—

Knowledge Not comparable

Claude Opus 4: 44.0 (#88), GPT-5.2 Codex: —

Knowledge benchmarks
BenchmarkClaude Opus 4GPT-5.2 Codex
GPQA Diamond76.3%—
Humanity's Last Exam10.7%—
MMLU-Pro87.5%—
Confabulations15.9%—
Vectara Hallucination Rate12%—
GPQA (HELM)70.8%—
LMArena Expert1386—

Multimodal Not comparable

Claude Opus 4: 31.5 (#106), GPT-5.2 Codex: —

Multimodal benchmarks
BenchmarkClaude Opus 4GPT-5.2 Codex
LMArena Vision1192—
GeoBench49%—
VPCT38%—

Multilingual Not comparable

Claude Opus 4: 48.8 (#138), GPT-5.2 Codex: —

Multilingual benchmarks
BenchmarkClaude Opus 4GPT-5.2 Codex
LMArena Non-English1362—
LMArena Chinese1386—
LMArena French1372—
LMArena German1391—
LMArena Japanese1331—
LMArena Korean1321—
LMArena Russian1392—
LMArena Spanish1389—

Instruction Following Not comparable

Claude Opus 4: 77.1 (#28), GPT-5.2 Codex: —

Instruction Following benchmarks
BenchmarkClaude Opus 4GPT-5.2 Codex
IFEval91.8%—
LMArena Instruction Following1406—

Long Context Not comparable

Claude Opus 4: 39.6 (#172), GPT-5.2 Codex: —

Long Context benchmarks
BenchmarkClaude Opus 4GPT-5.2 Codex
Fiction.LiveBench61.1%—
LMArena Longer Query1422—

Writing & Preference Not comparable

Claude Opus 4: 61.2 (#89), GPT-5.2 Codex: —

Writing & Preference benchmarks
BenchmarkClaude Opus 4GPT-5.2 Codex
LMArena Text1377—
LMArena Creative Writing1387—
Short-Story Creative Writing83.6%—
EQ-Bench Creative Writing1580—
WildBench85.2%—
LMArena Multi-Turn1396—

Frequently asked questions

Is Claude Opus 4 better than GPT-5.2 Codex?

Claude Opus 4 and GPT-5.2 Codex score almost the same on the Noometry Index (43.1 vs 42.6), so choose on price, context window or the category you care about most.

Which is cheaper, Claude Opus 4 or GPT-5.2 Codex?

GPT-5.2 Codex is cheaper. It lists at $1.75 per million input tokens and $14 per million output tokens; Claude Opus 4 lists at $15 and $75.

Is Claude Opus 4 or GPT-5.2 Codex better for coding?

Claude Opus 4 scores higher on coding benchmarks: 47.2 versus 45.5 in the Noometry coding category.

Which has the bigger context window?

GPT-5.2 Codex does, with 400K tokens against 200K.

How many benchmarks do Claude Opus 4 and GPT-5.2 Codex share?

1 benchmark has published results for both models. Claude Opus 4 has 56 scored results on Noometry and GPT-5.2 Codex has 5.

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