GPTvsGPT

GPT 5.5 vs o1

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

Pricing

Side-by-side pricing

GPT 5.5

Flagship

o1

Flagship
Input $/MTok
$5.00
$15.00
Output $/MTok
$30.00
$60.00
Cache discount
90% off
50% 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
o1

Guidance

When to use GPT 5.5 vs o1

Choose GPT 5.5 when...

  • -Cost matters: 67% cheaper on input tokens
  • -You need a larger context window (1,050K vs 200K)

Choose o1 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 5.5
o1
100K tokens
$1.25Cheaper
$2.85
1M tokens
$20.50Cheaper
$28.50
10M tokens
$205.00Cheaper
$285.00

FAQ

When should I use GPT 5.5 instead of o1?

GPT 5.5 and o1 perform similarly across all tracked tasks. Pick based on pricing and provider preference.

Is o1 cheaper than GPT 5.5?

o1 input costs $15.00/MTok, which is 200% more than GPT 5.5 at $5.00/MTok.

What are the context window sizes for GPT 5.5 and o1?

GPT 5.5 has a 1,050K token context window. o1 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.