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Gemini 3.5 Flash vs GPT-4o

Side-by-side API economics and benchmarks. Per-1M input and output rates, context window, and verified metrics.

Tale of the tape

Head-to-head specs pulled from each model profile.

Metric Gemini 3.5 Flash GPT-4o
Input cost / 1M $1.50 $2.50
Output cost / 1M $9.00 $10.00
Context window 1,048,576 tokens 128,000 tokens
MMLU score

Cost verdict

Enter monthly input and output volumes to see total cost savings.

Gemini 3.5 Flash

Input: 1M × $1.50 = $1.50
Output: 1M × $9.00 = $9.00
Total
$10.50

GPT-4o

Input: 1M × $2.50 = $2.50
Output: 1M × $10.00 = $10.00
Total
$12.50

Total cost savings

$2.00

Gemini 3.5 Flash saves $2.00 per month vs the other model at this volume.

Model routing savings

Uses this page's verified rates. GPT-4o is the premium route (higher combined per-1M cost); Gemini 3.5 Flash handles routine traffic.

Premium model

GPT-4o

$2.50 in · $10.00 out / 1M

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Economical model

Gemini 3.5 Flash

$1.50 in · $9.00 out / 1M

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All premium

GPT-4o

$625.00

100% of input and output on the premium route

Routed stack

80%Gemini 3.5 Flash

GPT-4o

$545.00

Routine slice
$420.00
Premium slice
$125.00

Monthly savings

$80.00

12.8% lower

Rates pulled from this page's model database entries (gpt-4o, gemini-3-5-flash) — same per-1M input/output figures as Tale of the tape. Production routing needs quality gates and monitoring.

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