tokevenGPTvsGPT
GPT 3.5 Turbo vs GPT 5.1
Side-by-side comparison of pricing, task quality, and projected cost at higher scale.
Pricing
Side-by-side pricing
GPT 3.5 Turbo
Fast / BudgetGPT 5.1
Mid-tierInput $/MTok
$0.50
$1.25
Output $/MTok
$1.50
$10.00
Cache discount
0% off
90% off
Context
16.385K
272K
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 3.5 Turbo
GPT 5.1
Guidance
When to use GPT 3.5 Turbo vs GPT 5.1
Choose GPT 3.5 Turbo when...
- -Cost matters: 60% cheaper on input tokens
Choose GPT 5.1 when...
- -You need a larger context window (272K vs 16.385K)
- 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 3.5 Turbo
GPT 5.1
100K tokens
$0.08Cheaper
$0.39
1M tokens
$0.80Cheaper
$3.88
10M tokens
$8.00Cheaper
$38.75
FAQ
When should I use GPT 3.5 Turbo instead of GPT 5.1?
GPT 3.5 Turbo and GPT 5.1 perform similarly across all tracked tasks. Pick based on pricing and provider preference.
Is GPT 5.1 cheaper than GPT 3.5 Turbo?
GPT 5.1 input costs $1.25/MTok, which is 150% more than GPT 3.5 Turbo at $0.50/MTok.
What are the context window sizes for GPT 3.5 Turbo and GPT 5.1?
GPT 3.5 Turbo has a 16.385K token context window. GPT 5.1 has a 272K 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 3.5 Turbo and GPT 5.1 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.