ClaudevsGPT

Claude Opus 4.8 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 4.8

Flagship

GPT 5.6 Luna

Fast / Budget
Input $/MTok
$5.00
$1.00
Output $/MTok
$25.00
$6.00
Cache discount
90% off
90% off
Context
200K
1,000K

Quality

Task confidence comparison

Confidence score from zero to one hundred by task type, where higher is better.
Code Generation
95
vs
70
Code Review
94
vs
68
Summarization
88
vs
84
Q&A
85
vs
85
Extraction
82
vs
89
Reasoning
97
vs
63
Classification
80
vs
91
Creative Writing
93
vs
58
Claude Opus 4.8
GPT 5.6 Luna

Guidance

When to use Claude Opus 4.8 vs GPT 5.6 Luna

Choose Claude Opus 4.8 when...

  • -You need strong reasoning (confidence 97 vs 63)
  • -You need strong code generation (confidence 95 vs 70)
  • -You need strong code review (confidence 94 vs 68)
  • -You need strong creative writing (confidence 93 vs 58)

Choose GPT 5.6 Luna when...

  • -You need strong classification (confidence 91 vs 80)
  • -You need strong extraction (confidence 89 vs 82)
  • -Cost matters: 80% cheaper on input tokens
  • -You need a larger context window (1,000K vs 200K)

At scale

Cost at scale

Estimated cost assuming a seventy percent input and thirty percent output token split.
Claude Opus 4.8
GPT 5.6 Luna
100K tokens
$1.10
$0.25Cheaper
1M tokens
$11.00
$2.50Cheaper
10M tokens
$110.00
$25.00Cheaper

FAQ

When should I use Claude Opus 4.8 instead of GPT 5.6 Luna?

Claude Opus 4.8 outperforms GPT 5.6 Luna for Reasoning, Code Generation, Code Review. It costs $5.00/$25.00 per million tokens (input/output).

Is GPT 5.6 Luna cheaper than Claude Opus 4.8?

Yes. GPT 5.6 Luna input costs $1.00/MTok vs $5.00/MTok for Claude Opus 4.8, saving 80% on input.

What are the context window sizes for Claude Opus 4.8 and GPT 5.6 Luna?

Claude Opus 4.8 has a 200K token context window. GPT 5.6 Luna has a 1,000K token context window.

Track your real costs

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