Model comparison

Claude Sonnet 4.6 vs GPT-5.2 Codex

Claude Sonnet 4.6 is the stronger model overall, scoring 50.3 to 42.6 on the Noometry Index.

Last verified . 3 shared benchmarks.

Claude Sonnet 4.6 Anthropic

50.3

Rank #50 Confirmed

GPT-5.2 Codex OpenAI

42.6

Rank #111 Reported

Summary

  • They share 3 benchmarks with published results for both. Claude Sonnet 4.6 scores higher in 1 category and GPT-5.2 Codex in 1 category; one gap is clear of the uncertainty.
  • The biggest single-benchmark swing is Terminal-Bench: 53.4% for Claude Sonnet 4.6 and 66.5% for GPT-5.2 Codex.
  • GPT-5.2 Codex is cheaper at $1.75 / $14 per million input/output tokens, against $3 / $15 for Claude Sonnet 4.6.
  • Claude Sonnet 4.6 accepts more context: 1M tokens versus 400K.

Side by side

Claude Sonnet 4.6 and GPT-5.2 Codex specifications
Claude Sonnet 4.6GPT-5.2 Codex
ProviderAnthropicOpenAI
Noometry Index50.342.6
Released2026-02-172025-12-18
WeightsProprietaryProprietary
Context window1M400K
Max output128K128K
Input $ / M tokens$3$1.75
Output $ / M tokens$15$14
Results tracked575

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Category by category

Coding Too close to call

Claude Sonnet 4.6: 46.3 (#67), GPT-5.2 Codex: 45.5 (#71)

Coding benchmarks
BenchmarkClaude Sonnet 4.6GPT-5.2 Codex
LMArena WebDev15221339
ALE-Bench1,3271,300
SWE-bench Verified75.2%—
DeepSWE29.9%—
FrontierCode24.3%—
SWE-bench Verified (bash only)—72.8%
SWE-bench Multilingual—66.3%
SciCode46.8%—
WeirdML66.1%—
LMArena Coding1504—

Agentic & Tool Use GPT-5.2 Codex leads

Claude Sonnet 4.6: 39.1 (#28), GPT-5.2 Codex: 41.0 (#22)

Agentic & Tool Use benchmarks
BenchmarkClaude Sonnet 4.6GPT-5.2 Codex
Terminal-Bench53.4%66.5%
APEX-Agents43%—
OSWorld 2.09.3%—
DeepResearch Bench54.9%—
OSWorld72.1%—
ExploitBench23.6%—
GBAEval48.8%—
GDP.pdf18%—
LMArena Search1221—
Vending-Bench 27,204—

Reasoning Not comparable

Claude Sonnet 4.6: 46.1 (#45), GPT-5.2 Codex: —

Reasoning benchmarks
BenchmarkClaude Sonnet 4.6GPT-5.2 Codex
ARC-AGI-260.4%—
NYT Connections (extended)80.9%—
ARC-AGI-186.5%—
CritPt3.1%—
Chess Puzzles13%—
Thematic Generalization76.3%—
LMArena Hard Prompts1484—
Mystery Game Puzzles16%—
DTBench89.9%—
LMCA46.5%—
Epoch Capabilities Index152.24—
ForecastBench62—

Math Not comparable

Claude Sonnet 4.6: 52.9 (#49), GPT-5.2 Codex: —

Math benchmarks
BenchmarkClaude Sonnet 4.6GPT-5.2 Codex
OTIS Mock AIME 2024-202585.8%—
ProofBench45%—
LMArena Math1462—
FrontierMath (Feb 2025 set)32.4%—
FrontierMath Tier 4 (v1)8.3%—

Knowledge Not comparable

Claude Sonnet 4.6: 51.7 (#65), GPT-5.2 Codex: —

Knowledge benchmarks
BenchmarkClaude Sonnet 4.6GPT-5.2 Codex
GPQA Diamond87.4%—
SimpleQA Verified35.5%—
Vectara Hallucination Rate10.6%—
LMArena Expert1500—

Multimodal Not comparable

Claude Sonnet 4.6: 38.0 (#68), GPT-5.2 Codex: —

Multimodal benchmarks
BenchmarkClaude Sonnet 4.6GPT-5.2 Codex
LMArena Vision1283—
Blueprint-Bench 26.7%—
LMArena Document1482—

Multilingual Not comparable

Claude Sonnet 4.6: 54.4 (#41), GPT-5.2 Codex: —

Multilingual benchmarks
BenchmarkClaude Sonnet 4.6GPT-5.2 Codex
LMArena Non-English1440—
LMArena Chinese1491—
LMArena French1465—
LMArena German1428—
LMArena Japanese1420—
LMArena Korean1411—
LMArena Russian1440—
LMArena Spanish1464—

Instruction Following Not comparable

Claude Sonnet 4.6: 77.4 (#25), GPT-5.2 Codex: —

Instruction Following benchmarks
BenchmarkClaude Sonnet 4.6GPT-5.2 Codex
LMArena Instruction Following1475—

Long Context Not comparable

Claude Sonnet 4.6: 45.3 (#44), GPT-5.2 Codex: —

Long Context benchmarks
BenchmarkClaude Sonnet 4.6GPT-5.2 Codex
LMArena Longer Query1479—

Writing & Preference Not comparable

Claude Sonnet 4.6: 70.2 (#22), GPT-5.2 Codex: —

Writing & Preference benchmarks
BenchmarkClaude Sonnet 4.6GPT-5.2 Codex
LMArena Text1458—
LMArena Creative Writing1435—
EQ-Bench Creative Writing1810—
EQ-Bench 41207—
LMArena Multi-Turn1464—

Frequently asked questions

Is Claude Sonnet 4.6 better than GPT-5.2 Codex?

Claude Sonnet 4.6 is the stronger model overall, scoring 50.3 to 42.6 on the Noometry Index.

Which is cheaper, Claude Sonnet 4.6 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 Sonnet 4.6 lists at $3 and $15.

Is Claude Sonnet 4.6 or GPT-5.2 Codex better for coding?

They score almost the same on coding (46.3 vs 45.5); test both on your own repository before choosing.

Which has the bigger context window?

Claude Sonnet 4.6 does, with 1M tokens against 400K.

How many benchmarks do Claude Sonnet 4.6 and GPT-5.2 Codex share?

3 benchmarks have published results for both models. Claude Sonnet 4.6 has 57 scored results on Noometry and GPT-5.2 Codex has 5.

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