tokevenGPTvsGPT
GPT 5.1 vs o3
Side-by-side comparison of pricing, task quality, and projected cost at higher scale.
Pricing
Side-by-side pricing
GPT 5.1
Mid-tiero3
Mid-tierInput $/MTok
$1.25
$2.00
Output $/MTok
$10.00
$8.00
Cache discount
90% off
75% off
Context
272K
200K
Quality
Task confidence comparison
Confidence score from zero to one hundred by task type, where higher is better.
Code Generation
0
vs
0
Code Review
0
vs
0
Summarization
0
vs
0
Q&A
0
vs
0
Extraction
0
vs
0
Reasoning
0
vs
0
Classification
0
vs
0
Creative Writing
0
vs
0
GPT 5.1
o3
Guidance
When to use GPT 5.1 vs o3
Choose GPT 5.1 when...
- -Cost matters: 38% cheaper on input tokens
- -You need a larger context window (272K 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 5.1
o3
100K tokens
$0.39
$0.38Cheaper
1M tokens
$3.88
$3.80Cheaper
10M tokens
$38.75
$38.00Cheaper
FAQ
When should I use GPT 5.1 instead of o3?
GPT 5.1 and o3 perform similarly across all tracked tasks. Pick based on pricing and provider preference.
Is o3 cheaper than GPT 5.1?
o3 input costs $2.00/MTok, which is 60% more than GPT 5.1 at $1.25/MTok.
What are the context window sizes for GPT 5.1 and o3?
GPT 5.1 has a 272K token context window. o3 has a 200K token context window.
Go deeper on either model
Per-call cost calculators, provider lineups, and price history for both models on this page.
Other comparisons
How GPT 5.1 and o3 stack up against the rest of the field.
Track your real costs
Comparisons show estimated costs at list price. The dashboard reveals your real spend and savings.