Model comparison

Claude Opus 4.5 vs GPT-6 Luna

GPT-6 Luna is the stronger model overall, scoring 53.3 to 50.5 on the Noometry Index.

Last verified . 34 shared benchmarks.

Claude Opus 4.5 Anthropic

50.5

Rank #47 Confirmed

GPT-6 Luna OpenAI

53.3

Rank #36 Confirmed

Summary

  • They share 34 benchmarks with published results for both. Claude Opus 4.5 scores higher in 5 categories and GPT-6 Luna in 5 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in math, where GPT-6 Luna leads 76.1 to 38.6.
  • The biggest single-benchmark swing is FrontierMath Tier 4: 4.9% for Claude Opus 4.5 and 56.1% for GPT-6 Luna.
  • GPT-6 Luna is cheaper at $0.10 / $0.50 per million input/output tokens, against $5 / $25 for Claude Opus 4.5.
  • GPT-6 Luna accepts more context: 1.05M tokens versus 200K.

Side by side

Claude Opus 4.5 and GPT-6 Luna specifications
Claude Opus 4.5GPT-6 Luna
ProviderAnthropicOpenAI
Noometry Index50.553.3
Released2025-11-012026-09-22
WeightsProprietaryProprietary
Context window200K1.05M
Max output64K128K
Input $ / M tokens$5$0.10
Output $ / M tokens$25$0.50
Results tracked6942

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Category by category

Coding Too close to call

Claude Opus 4.5: 54.8 (#27), GPT-6 Luna: 55.5 (#25)

Coding benchmarks
BenchmarkClaude Opus 4.5GPT-6 Luna
LMArena WebDev14941581
LMArena Coding15041439
ALE-Bench1,0251,577
SWE-bench Verified76.7%—
DeepSWE—66.6%
FrontierCode—42.4%
SWE-bench Verified (bash only)76.8%—
SWE-bench Multilingual70.7%—
SciCode—54.6%
GSO26.5%—
WeirdML63.7%—
AlgoTune1.77—

Agentic & Tool Use Claude Opus 4.5 leads

Claude Opus 4.5: 47.3 (#12), GPT-6 Luna: 33.3 (#54)

Agentic & Tool Use benchmarks
BenchmarkClaude Opus 4.5GPT-6 Luna
Terminal-Bench63.1%—
APEX-Agents—44.3%
Berkeley Function Calling Leaderboard77.5%—
GDPval45.5%—
Remote Labor Index3.8%—
τ²-bench Airline84%—
τ²-bench Banking24.7%—
τ²-bench Retail79.6%—
τ²-bench Telecom92.3%—
Cybench82%—
DeepResearch Bench54.8%—
OSWorld66.3%—
BALROG43.5%—
GDP.pdf—23%
LMArena Search1180—
METR Time Horizons75%—
Vending-Bench 24,967—

Reasoning GPT-6 Luna leads

Claude Opus 4.5: 42.6 (#51), GPT-6 Luna: 48.2 (#41)

Reasoning benchmarks
BenchmarkClaude Opus 4.5GPT-6 Luna
ARC-AGI-237.6%59.3%
NYT Connections (extended)52.5%68.7%
ARC-AGI-180%86.7%
Chess Puzzles12%31%
LMArena Hard Prompts14761411
Mystery Game Puzzles22%7%
DTBench89.9%90.1%
LMCA44.5%44.5%
Epoch Capabilities Index150.09156.28
SimpleBench62%—
Kagi LLM Benchmark80.2%—
CritPt—19.4%
EnigmaEval11.9%—
EBR-Bench14.3%—
ForecastBench60.7—

Math GPT-6 Luna leads

Claude Opus 4.5: 38.6 (#132), GPT-6 Luna: 76.1 (#15)

Math benchmarks
BenchmarkClaude Opus 4.5GPT-6 Luna
FrontierMath (Tiers 1-3)34.4%78.9%
FrontierMath Tier 44.9%56.1%
OTIS Mock AIME 2024-202586.1%98.9%
ProofBench36%64%
LMArena Math14631416
FrontierMath (Feb 2025 set)20.7%—
FrontierMath Tier 4 (v1)4.2%—

Knowledge Too close to call

Claude Opus 4.5: 56.5 (#44), GPT-6 Luna: 57.0 (#41)

Knowledge benchmarks
BenchmarkClaude Opus 4.5GPT-6 Luna
GPQA Diamond86%90.5%
SimpleQA Verified45.7%41.4%
LMArena Expert14871444
Humanity's Last Exam25.2%—
Vectara Hallucination Rate10.9%—

Multimodal GPT-6 Luna leads

Claude Opus 4.5: 31.4 (#107), GPT-6 Luna: 42.4 (#30)

Multimodal benchmarks
BenchmarkClaude Opus 4.5GPT-6 Luna
Furniture Assembly28.3%44.2%
LMArena Vision—1217
GeoBench75%—
VPCT40%—
Blueprint-Bench 2—31.2%
LMArena Document1462—

Multilingual Claude Opus 4.5 leads

Claude Opus 4.5: 54.3 (#47), GPT-6 Luna: 50.5 (#117)

Multilingual benchmarks
BenchmarkClaude Opus 4.5GPT-6 Luna
LMArena Non-English14381386
LMArena Chinese14701433
LMArena French14711420
LMArena German14491369
LMArena Japanese14161369
LMArena Korean14241360
LMArena Russian14471394
LMArena Spanish14581393

Instruction Following Claude Opus 4.5 leads

Claude Opus 4.5: 77.5 (#19), GPT-6 Luna: 74.3 (#99)

Instruction Following benchmarks
BenchmarkClaude Opus 4.5GPT-6 Luna
LMArena Instruction Following14781409

Long Context Claude Opus 4.5 leads

Claude Opus 4.5: 46.5 (#22), GPT-6 Luna: 43.0 (#111)

Long Context benchmarks
BenchmarkClaude Opus 4.5GPT-6 Luna
LMArena Longer Query14801409
CL-bench21.1%—

Writing & Preference Claude Opus 4.5 leads

Claude Opus 4.5: 68.1 (#28), GPT-6 Luna: 58.3 (#119)

Writing & Preference benchmarks
BenchmarkClaude Opus 4.5GPT-6 Luna
LMArena Text14511391
LMArena Creative Writing14451363
LMArena Multi-Turn14661396
EQ-Bench Creative Writing1687—

Frequently asked questions

Is Claude Opus 4.5 better than GPT-6 Luna?

GPT-6 Luna is the stronger model overall, scoring 53.3 to 50.5 on the Noometry Index.

Which is cheaper, Claude Opus 4.5 or GPT-6 Luna?

GPT-6 Luna is cheaper. It lists at $0.10 per million input tokens and $0.50 per million output tokens; Claude Opus 4.5 lists at $5 and $25.

Is Claude Opus 4.5 or GPT-6 Luna better for coding?

They score almost the same on coding (54.8 vs 55.5); test both on your own repository before choosing.

Which has the bigger context window?

GPT-6 Luna does, with 1.05M tokens against 200K.

How many benchmarks do Claude Opus 4.5 and GPT-6 Luna share?

34 benchmarks have published results for both models. Claude Opus 4.5 has 69 scored results on Noometry and GPT-6 Luna has 42.

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