tokevenGeminivsGemini
Gemini 3.1 Pro vs Gemini 3.5 Flash
Side-by-side comparison of pricing, task quality, and projected cost at higher scale.
Pricing
Side-by-side pricing
Gemini 3.1 Pro
Mid-tierGemini 3.5 Flash
Fast / BudgetInput $/MTok
$2.00
$1.50
Output $/MTok
$12.00
$9.00
Cache discount
90% off
90% off
Context
1.0M
1.0M
Quality
Task confidence comparison
Confidence score from zero to one hundred by task type, where higher is better.
Code Generation
57
vs
61
Code Review
84
vs
65
Summarization
80
vs
76
Q&A
87
vs
84
Extraction
75
vs
73
Reasoning
84
vs
82
Classification
86
vs
92
Creative Writing
77
vs
75
Gemini 3.1 Pro
Gemini 3.5 Flash
Guidance
When to use Gemini 3.1 Pro vs Gemini 3.5 Flash
Choose Gemini 3.1 Pro when...
- -You need strong q&a (confidence 87 vs 84)
- -You need strong code review (confidence 84 vs 65)
- -You need strong reasoning (confidence 84 vs 82)
- -You need strong summarization (confidence 80 vs 76)
Choose Gemini 3.5 Flash when...
- -You need strong classification (confidence 92 vs 86)
- -You need strong code generation (confidence 61 vs 57)
- -Cost matters: 25% cheaper on input tokens
At scale
Cost at scale
Estimated cost assuming a seventy percent input and thirty percent output token split.
Gemini 3.1 Pro
Gemini 3.5 Flash
100K tokens
$0.50
$0.38Cheaper
1M tokens
$8.20
$3.75Cheaper
10M tokens
$82.00
$37.50Cheaper
FAQ
When should I use Gemini 3.1 Pro instead of Gemini 3.5 Flash?
Gemini 3.1 Pro outperforms Gemini 3.5 Flash for Code Review, Summarization, Q&A. It costs $2.00/$12.00 per million tokens (input/output).
Is Gemini 3.5 Flash cheaper than Gemini 3.1 Pro?
Yes. Gemini 3.5 Flash input costs $1.50/MTok vs $2.00/MTok for Gemini 3.1 Pro, saving 25% on input.
What are the context window sizes for Gemini 3.1 Pro and Gemini 3.5 Flash?
Gemini 3.1 Pro has a 1.0M token context window. Gemini 3.5 Flash has a 1.0M 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 Gemini 3.1 Pro and Gemini 3.5 Flash 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.