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
1,000K
1,050K

Quality

Task confidence comparison

Confidence score from zero to one hundred by task type, where higher is better.
Code Generation
0
vs
70
Code Review
0
vs
68
Summarization
0
vs
84
Q&A
0
vs
85
Extraction
0
vs
89
Reasoning
0
vs
63
Classification
0
vs
91
Creative Writing
0
vs
58
Claude Opus 5
GPT 5.6 Luna

Guidance

When to use Claude Opus 5 vs GPT 5.6 Luna

Choose Claude Opus 5 when...

  • Similar performance; consider provider preference or ecosystem fit.

Choose GPT 5.6 Luna when...

  • -Cost matters: 96% cheaper on input tokens
  • -You need a larger context window (1,050K vs 1,000K)

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 and GPT 5.6 Luna perform similarly across all tracked tasks. Pick based on pricing and provider preference.

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 1,000K token context window. GPT 5.6 Luna has a 1,050K token context window.

Track your real costs

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