GPTvsGrok

GPT 5.6 Luna vs Grok 4.5

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

Grok 4.5

Flagship
Input $/MTok
$0.20
$2.00
Output $/MTok
$1.20
$6.00
Cache discount
90% off
85% off
Context
1,050K
500K

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
Grok 4.5

Guidance

When to use GPT 5.6 Luna vs Grok 4.5

Choose GPT 5.6 Luna when...

  • -Cost matters: 90% cheaper on input tokens
  • -You need a larger context window (1,050K vs 500K)

Choose Grok 4.5 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
Grok 4.5
100K tokens
$0.05Cheaper
$0.32
1M tokens
$0.82Cheaper
$6.40
10M tokens
$8.20Cheaper
$64.00

FAQ

When should I use GPT 5.6 Luna instead of Grok 4.5?

GPT 5.6 Luna and Grok 4.5 perform similarly across all tracked tasks. Pick based on pricing and provider preference.

Is Grok 4.5 cheaper than GPT 5.6 Luna?

Grok 4.5 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 Grok 4.5?

GPT 5.6 Luna has a 1,050K token context window. Grok 4.5 has a 500K token context window.

Track your real costs

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