Model comparison

Claude Sonnet 4.5 vs GPT-6 Luna

GPT-6 Luna is the stronger model overall, scoring 53.3 to 44.1 on the Noometry Index.

Last verified . 35 shared benchmarks.

Claude Sonnet 4.5 Anthropic

44.1

Rank #81 Confirmed

GPT-6 Luna OpenAI

53.3

Rank #36 Confirmed

Summary

  • They share 35 benchmarks with published results for both. Claude Sonnet 4.5 scores higher in 5 categories and GPT-6 Luna in 5 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in math, where GPT-6 Luna leads 76.1 to 32.3.
  • The biggest single-benchmark swing is FrontierMath (Tiers 1-3): 23.9% for Claude Sonnet 4.5 and 78.9% for GPT-6 Luna.
  • GPT-6 Luna is cheaper at $0.10 / $0.50 per million input/output tokens, against $3 / $15 for Claude Sonnet 4.5.
  • GPT-6 Luna accepts more context: 1.05M tokens versus 200K.

Side by side

Claude Sonnet 4.5 and GPT-6 Luna specifications
Claude Sonnet 4.5GPT-6 Luna
ProviderAnthropicOpenAI
Noometry Index44.153.3
Released2025-09-292026-09-22
WeightsProprietaryProprietary
Context window200K1.05M
Max output64K128K
Input $ / M tokens$3$0.10
Output $ / M tokens$15$0.50
Results tracked7342

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Category by category

Coding GPT-6 Luna leads

Claude Sonnet 4.5: 47.3 (#61), GPT-6 Luna: 55.5 (#25)

Coding benchmarks
BenchmarkClaude Sonnet 4.5GPT-6 Luna
LMArena WebDev13931581
SciCode44.7%54.6%
LMArena Coding14891439
ALE-Bench796.151,577
SWE-bench Verified71.3%—
DeepSWE—66.6%
FrontierCode—42.4%
SWE-bench Verified (bash only)71.4%—
SWE-bench Multilingual67%—
GSO14.7%—
WeirdML47.7%—
AlgoTune1.52—

Agentic & Tool Use Claude Sonnet 4.5 leads

Claude Sonnet 4.5: 38.3 (#32), GPT-6 Luna: 33.3 (#54)

Agentic & Tool Use benchmarks
BenchmarkClaude Sonnet 4.5GPT-6 Luna
Terminal-Bench46.5%—
APEX-Agents—44.3%
Berkeley Function Calling Leaderboard73.2%—
GDPval42.5%—
Remote Labor Index2.1%—
τ²-bench Airline72%—
τ²-bench Banking25.3%—
τ²-bench Retail72.4%—
τ²-bench Telecom84.9%—
Cybench60%—
DeepResearch Bench52.6%—
OSWorld62.9%—
GDP.pdf—23%
LMArena Search1159—
METR Time Horizons67.4%—
Vending-Bench 23,839—

Reasoning GPT-6 Luna leads

Claude Sonnet 4.5: 26.9 (#125), GPT-6 Luna: 48.2 (#41)

Reasoning benchmarks
BenchmarkClaude Sonnet 4.5GPT-6 Luna
ARC-AGI-213.6%59.3%
NYT Connections (extended)37.3%68.7%
ARC-AGI-163.7%86.7%
CritPt1.1%19.4%
Chess Puzzles12%31%
LMArena Hard Prompts14621411
Mystery Game Puzzles17%7%
DTBench83.2%90.1%
LMCA38.8%44.5%
Epoch Capabilities Index146.84156.28
SimpleBench54.3%—
Kagi LLM Benchmark57.9%—
EnigmaEval6%—
EBR-Bench2.4%—
ForecastBench61.9—

Math GPT-6 Luna leads

Claude Sonnet 4.5: 32.3 (#216), GPT-6 Luna: 76.1 (#15)

Math benchmarks
BenchmarkClaude Sonnet 4.5GPT-6 Luna
FrontierMath (Tiers 1-3)23.9%78.9%
FrontierMath Tier 42.4%56.1%
OTIS Mock AIME 2024-202577.8%98.9%
ProofBench19%64%
LMArena Math14491416
Omni-MATH55.3%—
MATH Level 597.7%—
FrontierMath (Feb 2025 set)15.2%—
FrontierMath Tier 4 (v1)4.2%—

Knowledge GPT-6 Luna leads

Claude Sonnet 4.5: 48.4 (#76), GPT-6 Luna: 57.0 (#41)

Knowledge benchmarks
BenchmarkClaude Sonnet 4.5GPT-6 Luna
GPQA Diamond82.3%90.5%
SimpleQA Verified30.7%41.4%
LMArena Expert14821444
Humanity's Last Exam13.7%—
MMLU-Pro86.9%—
Vectara Hallucination Rate12%—
GPQA (HELM)68.6%—

Multimodal GPT-6 Luna leads

Claude Sonnet 4.5: 34.8 (#89), GPT-6 Luna: 42.4 (#30)

Multimodal benchmarks
BenchmarkClaude Sonnet 4.5GPT-6 Luna
LMArena Vision—1217
VPCT39.8%—
Blueprint-Bench 2—31.2%
Furniture Assembly—44.2%
LMArena Document1450—

Multilingual Claude Sonnet 4.5 leads

Claude Sonnet 4.5: 53.4 (#69), GPT-6 Luna: 50.5 (#117)

Multilingual benchmarks
BenchmarkClaude Sonnet 4.5GPT-6 Luna
LMArena Non-English14251386
LMArena Chinese14591433
LMArena French14581420
LMArena German14271369
LMArena Japanese13901369
LMArena Korean14031360
LMArena Russian14371394
LMArena Spanish14571393

Instruction Following Too close to call

Claude Sonnet 4.5: 75.0 (#78), GPT-6 Luna: 74.3 (#99)

Instruction Following benchmarks
BenchmarkClaude Sonnet 4.5GPT-6 Luna
LMArena Instruction Following14591409
IFEval85%—

Long Context Claude Sonnet 4.5 leads

Claude Sonnet 4.5: 45.2 (#46), GPT-6 Luna: 43.0 (#111)

Long Context benchmarks
BenchmarkClaude Sonnet 4.5GPT-6 Luna
LMArena Longer Query14761409

Writing & Preference Claude Sonnet 4.5 leads

Claude Sonnet 4.5: 66.5 (#34), GPT-6 Luna: 58.3 (#119)

Writing & Preference benchmarks
BenchmarkClaude Sonnet 4.5GPT-6 Luna
LMArena Text14391391
LMArena Creative Writing14421363
LMArena Multi-Turn14651396
EQ-Bench Creative Writing1678—
WildBench85.4%—

Frequently asked questions

Is Claude Sonnet 4.5 better than GPT-6 Luna?

GPT-6 Luna is the stronger model overall, scoring 53.3 to 44.1 on the Noometry Index.

Which is cheaper, Claude Sonnet 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 Sonnet 4.5 lists at $3 and $15.

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

GPT-6 Luna scores higher on coding benchmarks: 55.5 versus 47.3 in the Noometry coding category.

Which has the bigger context window?

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

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

35 benchmarks have published results for both models. Claude Sonnet 4.5 has 73 scored results on Noometry and GPT-6 Luna has 42.

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