gemini-2.5-flash vs gemini-3.5-flash

Google Gemini against Google Gemini, priced on the same four workloads with price book 2026-10-22.

On real workloads

Workloadgemini-2.5-flash per callgemini-3.5-flash per callMonthly difference
Chat reply
1,500 input and 400 output tokens, 100,000 calls a month
$0.00145$0.00585 $440.00
RAG answer, cached context
2,000 fresh + 4,000 cached input, 500 output, 100,000 calls a month
$0.00197$0.0081 $613.00
Agent step
4,000 fresh + 8,000 cached input, 800 output, 250,000 calls a month
$0.00344$0.01 $2,740.00
Batch summary
3,000 input and 300 output tokens via the Batch API, 1,000,000 calls a month
$0.000825$0.0036 $2,775.00

Monthly difference is gemini-3.5-flash minus gemini-2.5-flash. Batch rows use each provider's Batch API rates where published. Price both on your own workload.

Rates

ModelInputOutputCache readCache writeContext
google/gemini-2.5-flash$0.30$2.50$0.03—1M
google/gemini-3.5-flash$1.50$9.00$0.15—1M

Price is one input. Before switching, run your own prompts through both and compare quality; then veqen diff prices the change at your production volume.