GPTvsGPT

GPT 5.6 Luna vs o3 Pro

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

Pricing

Side-by-side pricing

GPT 5.6 Luna

Fast / Budget

o3 Pro

Flagship
Input $/MTok
$0.20
$20.00
Output $/MTok
$1.20
$80.00
Cache discount
90% off
0% off
Context
922K
200K

Quality

Task confidence comparison

Confidence score from zero to one hundred by task type, where higher is better.
Code Generation
70
vs
0
Code Review
68
vs
0
Summarization
84
vs
0
Q&A
85
vs
0
Extraction
89
vs
0
Reasoning
63
vs
0
Classification
91
vs
0
Creative Writing
58
vs
0
GPT 5.6 Luna
o3 Pro

Guidance

When to use GPT 5.6 Luna vs o3 Pro

Choose GPT 5.6 Luna when...

  • -Cost matters: 99% cheaper on input tokens
  • -You need a larger context window (922K vs 200K)

Choose o3 Pro when...

  • Similar performance; consider provider preference or ecosystem fit.

At scale

Cost at scale

Estimated cost assuming a seventy percent input and thirty percent output token split.
GPT 5.6 Luna
o3 Pro
100K tokens
$0.05Cheaper
$3.80
1M tokens
$0.82Cheaper
$38.00
10M tokens
$8.20Cheaper
$380.00

FAQ

When should I use GPT 5.6 Luna instead of o3 Pro?

GPT 5.6 Luna and o3 Pro perform similarly across all tracked tasks. Pick based on pricing and provider preference.

Is o3 Pro cheaper than GPT 5.6 Luna?

o3 Pro input costs $20.00/MTok, which is 9900% more than GPT 5.6 Luna at $0.20/MTok.

What are the context window sizes for GPT 5.6 Luna and o3 Pro?

GPT 5.6 Luna has a 922K token context window. o3 Pro has a 200K token context window.

Track your real costs

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