tokevenGPTvsGemini
GPT 4o vs Gemini 2.5 Flash
Side-by-side comparison of pricing, task quality, and projected cost at higher scale.
Pricing
Side-by-side pricing
GPT 4o
Mid-tierGemini 2.5 Flash
Fast / BudgetInput $/MTok
$2.50
$0.30
Output $/MTok
$10.00
$2.50
Cache discount
50% off
90% off
Context
128K
1,048.576K
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 4o
Gemini 2.5 Flash
Guidance
When to use GPT 4o vs Gemini 2.5 Flash
Choose GPT 4o when...
- Similar performance; consider provider preference or ecosystem fit.
Choose Gemini 2.5 Flash when...
- -Cost matters: 88% cheaper on input tokens
- -You need a larger context window (1,048.576K vs 128K)
At scale
Cost at scale
Estimated cost assuming a seventy percent input and thirty percent output token split.
GPT 4o
Gemini 2.5 Flash
100K tokens
$0.47
$0.10Cheaper
1M tokens
$4.75
$0.96Cheaper
10M tokens
$47.50
$9.60Cheaper
FAQ
When should I use GPT 4o instead of Gemini 2.5 Flash?
GPT 4o and Gemini 2.5 Flash perform similarly across all tracked tasks. Pick based on pricing and provider preference.
Is Gemini 2.5 Flash cheaper than GPT 4o?
Yes. Gemini 2.5 Flash input costs $0.30/MTok vs $2.50/MTok for GPT 4o, saving 88% on input.
What are the context window sizes for GPT 4o and Gemini 2.5 Flash?
GPT 4o has a 128K token context window. Gemini 2.5 Flash has a 1,048.576K 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 4o and Gemini 2.5 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.