Noometry

Model comparison

Claude Opus 4.6 vs GPT-5.1-Codex-mini

Claude Opus 4.6 has enough public results to be ranked (#20); GPT-5.1-Codex-mini does not yet, so treat this comparison as directional.

Last verified . 2 shared benchmarks.

Claude Opus 4.6 Anthropic

58.2

Rank #20 Confirmed

GPT-5.1-Codex-mini OpenAI

37.3

Unranked Sparse

Summary

  • They share 2 benchmarks with published results for both. Claude Opus 4.6 scores higher in 2 categories and GPT-5.1-Codex-mini in 0 categories; 2 gaps are clear of the uncertainty.
  • The widest gap is in coding, where Claude Opus 4.6 leads 57.2 to 31.6.
  • The biggest single-benchmark swing is Terminal-Bench: 79.8% for Claude Opus 4.6 and 61.6% for GPT-5.1-Codex-mini.
  • GPT-5.1-Codex-mini is cheaper at $0.25 / $2 per million input/output tokens, against $5 / $25 for Claude Opus 4.6.
  • Claude Opus 4.6 accepts more context: 1M tokens versus 400K.

Side by side

Claude Opus 4.6GPT-5.1-Codex-mini
ProviderAnthropicOpenAI
Noometry Index58.237.3
Released2026-02-042025-11-12
WeightsProprietaryProprietary
Context window1M400K
Max output128K128K
Input $ / M tokens$5$0.25
Output $ / M tokens$25$2
Results tracked682

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Category by category

Coding Claude Opus 4.6 leads

Claude Opus 4.6: 57.2 (#20), GPT-5.1-Codex-mini: 31.6

BenchmarkClaude Opus 4.6GPT-5.1-Codex-mini
LMArena WebDev15471244
SWE-bench Verified78.7%—
FrontierCode26.6%—
SWE-bench Verified (bash only)75.6%—
SWE-bench Multilingual72%—
GSO41.2%—
WeirdML78%—
LMArena Coding1536—
ALE-Bench996.5—
AlgoTune1.47—

Agentic & Tool Use Claude Opus 4.6 leads

Claude Opus 4.6: 51.1 (#4), GPT-5.1-Codex-mini: 38.5

BenchmarkClaude Opus 4.6GPT-5.1-Codex-mini
Terminal-Bench79.8%61.6%
APEX-Agents46.3%—
Remote Labor Index4.2%—
τ²-bench Banking27.3%—
Cybench93%—
DeepResearch Bench55.3%—
GBAEval44.1%—
LMArena Search1253—
METR Time Horizons78.9%—
Vending-Bench 28,018—

Reasoning Not comparable

Claude Opus 4.6: 57.8 (#23), GPT-5.1-Codex-mini: —

BenchmarkClaude Opus 4.6GPT-5.1-Codex-mini
ARC-AGI-269.2%—
SimpleBench67.6%—
Kagi LLM Benchmark83.6%—
NYT Connections (extended)92.1%—
ARC-AGI-194%—
Chess Puzzles17%—
EnigmaEval7.6%—
Thematic Generalization80.6%—
EBR-Bench12.7%—
LMArena Hard Prompts1527—
Mystery Game Puzzles25%—
DTBench91.2%—
LMCA55.8%—
Epoch Capabilities Index155.24—
ForecastBench60—

Math Not comparable

Claude Opus 4.6: 63.0 (#31), GPT-5.1-Codex-mini: —

BenchmarkClaude Opus 4.6GPT-5.1-Codex-mini
FrontierMath (Tiers 1-3)66%—
FrontierMath Tier 426.8%—
MathArena Final-Answer Competitions78.5%—
OTIS Mock AIME 2024-202594.4%—
ProofBench50%—
LMArena Math1519—
FrontierMath (Feb 2025 set)40.7%—
FrontierMath Tier 4 (v1)22.9%—

Knowledge Not comparable

Claude Opus 4.6: 61.9 (#26), GPT-5.1-Codex-mini: —

BenchmarkClaude Opus 4.6GPT-5.1-Codex-mini
GPQA Diamond90.5%—
Humanity's Last Exam34.4%—
SimpleQA Verified47%—
Vectara Hallucination Rate12.2%—
LMArena Expert1546—

Multimodal Not comparable

Claude Opus 4.6: 37.3 (#74), GPT-5.1-Codex-mini: —

BenchmarkClaude Opus 4.6GPT-5.1-Codex-mini
LMArena Vision1316—
Furniture Assembly28.3%—
LMArena Document1507—

Multilingual Not comparable

Claude Opus 4.6: 57.9 (#6), GPT-5.1-Codex-mini: —

BenchmarkClaude Opus 4.6GPT-5.1-Codex-mini
LMArena Non-English1489—
LMArena Chinese1551—
LMArena French1513—
LMArena German1502—
LMArena Japanese1484—
LMArena Korean1464—
LMArena Russian1497—
LMArena Spanish1510—

Instruction Following Not comparable

Claude Opus 4.6: 79.5 (#4), GPT-5.1-Codex-mini: —

BenchmarkClaude Opus 4.6GPT-5.1-Codex-mini
LMArena Instruction Following1523—

Long Context Not comparable

Claude Opus 4.6: 48.1 (#13), GPT-5.1-Codex-mini: —

BenchmarkClaude Opus 4.6GPT-5.1-Codex-mini
CL-bench20.7%—
CL-bench Life17%—
LMArena Longer Query1520—

Writing & Preference Not comparable

Claude Opus 4.6: 73.5 (#10), GPT-5.1-Codex-mini: —

BenchmarkClaude Opus 4.6GPT-5.1-Codex-mini
LMArena Text1503—
LMArena Creative Writing1505—
EQ-Bench Creative Writing1809—
EQ-Bench 41223—
LMArena Multi-Turn1513—

Frequently asked questions

Is Claude Opus 4.6 better than GPT-5.1-Codex-mini?

Claude Opus 4.6 has enough public results to be ranked (#20); GPT-5.1-Codex-mini does not yet, so treat this comparison as directional.

Which is cheaper, Claude Opus 4.6 or GPT-5.1-Codex-mini?

GPT-5.1-Codex-mini is cheaper. It lists at $0.25 per million input tokens and $2 per million output tokens; Claude Opus 4.6 lists at $5 and $25.

Is Claude Opus 4.6 or GPT-5.1-Codex-mini better for coding?

Claude Opus 4.6 scores higher on coding benchmarks: 57.2 versus 31.6 in the Noometry coding category.

Which has the bigger context window?

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

How many benchmarks do Claude Opus 4.6 and GPT-5.1-Codex-mini share?

2 benchmarks have published results for both models. Claude Opus 4.6 has 68 scored results on Noometry and GPT-5.1-Codex-mini has 2.

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