Model comparison

Claude Opus 5 vs GPT-6 Luna

Claude Opus 5 is the stronger model overall, scoring 67.7 to 45.1 on the Noometry Index. GPT-6 Luna costs 50× less per token, which makes it the better buy when Claude Opus 5's lead doesn't matter for your workload.

Last verified . 18 shared benchmarks.

Claude Opus 5 Anthropic

67.7

Rank #4 Confirmed

GPT-6 Luna OpenAI

45.1

Rank #65 Confirmed

Summary

  • They share 18 benchmarks with published results for both. Claude Opus 5 scores higher in 9 categories and GPT-6 Luna in 0 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in math, where Claude Opus 5 leads 86.1 to 35.6.
  • The biggest single-benchmark swing is NYT Connections (extended): 94.3% for Claude Opus 5 and 68.7% 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 5.
  • GPT-6 Luna accepts more context: 1.05M tokens versus 1M.

Side by side

Claude Opus 5 and GPT-6 Luna specifications
Claude Opus 5GPT-6 Luna
ProviderAnthropicOpenAI
Noometry Index67.745.1
Released2026-07-242026-09-22
WeightsProprietaryProprietary
Context window1M1.05M
Max output128K128K
Input $ / M tokens$5$0.10
Output $ / M tokens$25$0.50
Results tracked5718

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Category by category

Coding Claude Opus 5 leads

Claude Opus 5: 67.0 (#5), GPT-6 Luna: 54.7 (#24)

Coding benchmarks
BenchmarkClaude Opus 5GPT-6 Luna
DeepSWE73.6%66.6%
FrontierCode53.4%42.4%
LMArena WebDev16941583
LMArena Coding15331448
CursorBench46.6%—
FrontierSWE52%—
SciCode56.4%—
WeirdML91.8%—
ALE-Bench2,165—

Agentic & Tool Use Not comparable

Claude Opus 5: 55.5 (#1), GPT-6 Luna: —

Agentic & Tool Use benchmarks
BenchmarkClaude Opus 5GPT-6 Luna
APEX-Agents65.8%—
OSWorld 2.031.4%—
τ²-bench Banking48.7%—
PostTrainBench35%—
BALROG63.4%—
GBAEval79.6%—
GDP.pdf24%—
Vending-Bench 211,182—

Reasoning Claude Opus 5 leads

Claude Opus 5: 77.1 (#3), GPT-6 Luna: 31.7 (#68)

Reasoning benchmarks
BenchmarkClaude Opus 5GPT-6 Luna
NYT Connections (extended)94.3%68.7%
LMArena Hard Prompts15251415
ARC-AGI-290.4%—
SimpleBench80.6%—
ARC-AGI-197.5%—
CritPt29.1%—
Chess Puzzles42%—
EBR-Bench45.7%—
Mystery Game Puzzles59%—
DTBench97.9%—
LMCA64.5%—
Bench to the Future 30.12—
Epoch Capabilities Index162.67—

Math Claude Opus 5 leads

Claude Opus 5: 86.1 (#6), GPT-6 Luna: 35.6 (#140)

Math benchmarks
BenchmarkClaude Opus 5GPT-6 Luna
LMArena Math15331396
FrontierMath (Tiers 1-3)85.6%—
FrontierMath Tier 473.2%—
OTIS Mock AIME 2024-202598.9%—
ProofBench99%—

Knowledge Claude Opus 5 leads

Claude Opus 5: 66.8 (#8), GPT-6 Luna: 40.1 (#110)

Knowledge benchmarks
BenchmarkClaude Opus 5GPT-6 Luna
LMArena Expert15581458
GPQA Diamond93.9%—
SimpleQA Verified59.9%—

Multimodal Claude Opus 5 leads

Claude Opus 5: 51.1 (#6), GPT-6 Luna: 42.0 (#27)

Multimodal benchmarks
BenchmarkClaude Opus 5GPT-6 Luna
Furniture Assembly60.8%44.2%
LMArena Vision1321—
Blueprint-Bench 230.4%—
LMArena Document1516—

Multilingual Claude Opus 5 leads

Claude Opus 5: 58.8 (#3), GPT-6 Luna: 51.0 (#111)

Multilingual benchmarks
BenchmarkClaude Opus 5GPT-6 Luna
LMArena Non-English15001390
LMArena Chinese15751425
LMArena Russian15071392
LMArena Spanish15191416
LMArena French1522—
LMArena German1522—
LMArena Japanese1510—
LMArena Korean1526—

Instruction Following Claude Opus 5 leads

Claude Opus 5: 79.3 (#5), GPT-6 Luna: 74.7 (#85)

Instruction Following benchmarks
BenchmarkClaude Opus 5GPT-6 Luna
LMArena Instruction Following15161414

Long Context Claude Opus 5 leads

Claude Opus 5: 46.5 (#20), GPT-6 Luna: 43.3 (#95)

Long Context benchmarks
BenchmarkClaude Opus 5GPT-6 Luna
LMArena Longer Query15161417

Writing & Preference Claude Opus 5 leads

Claude Opus 5: 79.3 (#2), GPT-6 Luna: 58.4 (#115)

Writing & Preference benchmarks
BenchmarkClaude Opus 5GPT-6 Luna
LMArena Text15061392
LMArena Creative Writing14911357
LMArena Multi-Turn14961400
EQ-Bench Creative Writing2133—
EQ-Bench 41385—

Frequently asked questions

Is Claude Opus 5 better than GPT-6 Luna?

Claude Opus 5 is the stronger model overall, scoring 67.7 to 45.1 on the Noometry Index. GPT-6 Luna costs 50× less per token, which makes it the better buy when Claude Opus 5's lead doesn't matter for your workload.

Which is cheaper, Claude Opus 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 5 lists at $5 and $25.

Is Claude Opus 5 or GPT-6 Luna better for coding?

Claude Opus 5 scores higher on coding benchmarks: 67.0 versus 54.7 in the Noometry coding category.

Which has the bigger context window?

GPT-6 Luna does, with 1.05M tokens against 1M.

How many benchmarks do Claude Opus 5 and GPT-6 Luna share?

18 benchmarks have published results for both models. Claude Opus 5 has 57 scored results on Noometry and GPT-6 Luna has 18.

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