GPTvsGPT

GPT 5.4 vs GPT 5.6 Luna

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

Pricing

Side-by-side pricing

GPT 5.4

Mid-tier

GPT 5.6 Luna

Fast / Budget
Input $/MTok
$2.50
$1.00
Output $/MTok
$15.00
$6.00
Cache discount
90% off
90% off
Context
128K
1,000K

Quality

Task confidence comparison

Confidence score from zero to one hundred by task type, where higher is better.
Code Generation
84
vs
70
Code Review
82
vs
68
Summarization
91
vs
84
Q&A
91
vs
85
Extraction
89
vs
89
Reasoning
80
vs
63
Classification
88
vs
91
Creative Writing
78
vs
58
GPT 5.4
GPT 5.6 Luna

Guidance

When to use GPT 5.4 vs GPT 5.6 Luna

Choose GPT 5.4 when...

  • -You need strong summarization (confidence 91 vs 84)
  • -You need strong q&a (confidence 91 vs 85)
  • -You need strong code generation (confidence 84 vs 70)
  • -You need strong code review (confidence 82 vs 68)

Choose GPT 5.6 Luna when...

  • -You need strong classification (confidence 91 vs 88)
  • -Cost matters: 60% cheaper on input tokens
  • -You need a larger context window (1,000K vs 128K)

At scale

Cost at scale

Estimated cost assuming a seventy percent input and thirty percent output token split.
GPT 5.4
GPT 5.6 Luna
100K tokens
$0.63
$0.25Cheaper
1M tokens
$6.25
$2.50Cheaper
10M tokens
$62.50
$25.00Cheaper

FAQ

When should I use GPT 5.4 instead of GPT 5.6 Luna?

GPT 5.4 outperforms GPT 5.6 Luna for Summarization, Q&A, Code Generation. It costs $2.50/$15.00 per million tokens (input/output).

Is GPT 5.6 Luna cheaper than GPT 5.4?

Yes. GPT 5.6 Luna input costs $1.00/MTok vs $2.50/MTok for GPT 5.4, saving 60% on input.

What are the context window sizes for GPT 5.4 and GPT 5.6 Luna?

GPT 5.4 has a 128K 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.