ClaudevsGPT

Claude Opus 5 vs GPT 5.6 Luna

Side-by-side comparison of pricing, task quality, and projected cost at higher scale.

Pricing

Side-by-side pricing

Claude Opus 5

Flagship

GPT 5.6 Luna

Fast / Budget
Input $/MTok
$5.00
$0.20
Output $/MTok
$25.00
$1.20
Cache discount
90% off
90% off
Context
1M
922K

Quality

Task confidence comparison

Confidence score from zero to one hundred by task type, where higher is better.
Code Generation
72
vs
62
Code Review
0
vs
68
Summarization
65
vs
57
Q&A
0
vs
85
Extraction
73
vs
74
Reasoning
91
vs
86
Classification
0
vs
91
Creative Writing
61
vs
69
Claude Opus 5
GPT 5.6 Luna

Guidance

When to use Claude Opus 5 vs GPT 5.6 Luna

Choose Claude Opus 5 when...

  • -You need strong reasoning (confidence 91 vs 86)
  • -You need strong code generation (confidence 72 vs 62)
  • -You need strong summarization (confidence 65 vs 57)
  • -You need a larger context window (1M vs 922K)

Choose GPT 5.6 Luna when...

  • -You need strong extraction (confidence 74 vs 73)
  • -You need strong creative writing (confidence 69 vs 61)
  • -Cost matters: 96% cheaper on input tokens

At scale

Cost at scale

Estimated cost assuming a seventy percent input and thirty percent output token split.
Claude Opus 5
GPT 5.6 Luna
100K tokens
$1.10
$0.05Cheaper
1M tokens
$11.00
$0.82Cheaper
10M tokens
$110.00
$8.20Cheaper

FAQ

When should I use Claude Opus 5 instead of GPT 5.6 Luna?

Claude Opus 5 outperforms GPT 5.6 Luna for Code Generation, Summarization, Reasoning. It costs $5.00/$25.00 per million tokens (input/output).

Is GPT 5.6 Luna cheaper than Claude Opus 5?

Yes. GPT 5.6 Luna input costs $0.20/MTok vs $5.00/MTok for Claude Opus 5, saving 96% on input.

What are the context window sizes for Claude Opus 5 and GPT 5.6 Luna?

Claude Opus 5 has a 1M token context window. GPT 5.6 Luna has a 922K token context window.

Track your real costs

Comparisons show estimated costs at list price. The dashboard reveals your real spend and savings.