GPTvsGPT

GPT 5.6 Luna vs o3

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

Mid-tier
Input $/MTok
$0.20
$2.00
Output $/MTok
$1.20
$8.00
Cache discount
90% off
75% 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

Guidance

When to use GPT 5.6 Luna vs o3

Choose GPT 5.6 Luna when...

  • -Cost matters: 90% cheaper on input tokens
  • -You need a larger context window (922K vs 200K)

Choose o3 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
100K tokens
$0.05Cheaper
$0.38
1M tokens
$0.82Cheaper
$3.80
10M tokens
$8.20Cheaper
$38.00

FAQ

When should I use GPT 5.6 Luna instead of o3?

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

Is o3 cheaper than GPT 5.6 Luna?

o3 input costs $2.00/MTok, which is 900% more than GPT 5.6 Luna at $0.20/MTok.

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

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