GPTvsGPT

GPT 5.5 vs o3

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

Pricing

Side-by-side pricing

GPT 5.5

Flagship

o3

Mid-tier
Input $/MTok
$5.00
$2.00
Output $/MTok
$30.00
$8.00
Cache discount
90% off
75% off
Context
1,050K
200K

Quality

Task confidence comparison

Confidence score from zero to one hundred by task type, where higher is better.
Code Generation
91
vs
0
Code Review
90
vs
0
Summarization
89
vs
0
Q&A
90
vs
0
Extraction
87
vs
0
Reasoning
95
vs
0
Classification
85
vs
0
Creative Writing
91
vs
0
GPT 5.5
o3

Guidance

When to use GPT 5.5 vs o3

Choose GPT 5.5 when...

  • -You need a larger context window (1,050K vs 200K)
  • Similar performance; consider provider preference or ecosystem fit.

Choose o3 when...

  • -Cost matters: 60% cheaper on input tokens

At scale

Cost at scale

Estimated cost assuming a seventy percent input and thirty percent output token split.
GPT 5.5
o3
100K tokens
$1.25
$0.38Cheaper
1M tokens
$20.50
$3.80Cheaper
10M tokens
$205.00
$38.00Cheaper

FAQ

When should I use GPT 5.5 instead of o3?

GPT 5.5 and o3 perform similarly across all tracked tasks. Pick based on pricing and provider preference.

Is o3 cheaper than GPT 5.5?

Yes. o3 input costs $2.00/MTok vs $5.00/MTok for GPT 5.5, saving 60% on input.

What are the context window sizes for GPT 5.5 and o3?

GPT 5.5 has a 1,050K 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.