Gemini 2.5 Flash vs Gemini 3.1 Flash Lite

API pricing, benchmark indices and specs — updated 19 October 2026.

google · A · API-only
Input / 1M
$0.30
Output / 1M
$2.50
AA index
15.5
proprietary · 1M context
google · B · API-only
Input / 1M
$0.25
Output / 1M
$1.50
AA index
—
proprietary · 1M context

Specification comparison

Differences are highlighted; identical values are muted.

Specification Gemini 2.5 Flash Gemini 3.1 Flash Lite
Deployment API-only (closed weights) API-only (closed weights)
Parameters n/a — API-only n/a — API-only
Architecture n/a — API-only n/a — API-only
Context length 1,048,576 1,048,576
Licence Proprietary Proprietary
Commercial use Per API terms Per API terms
Languages n/a — API-only n/a — API-only
Downloads 30d n/a — API-only n/a — API-only
Downloads all time n/a — API-only n/a — API-only
Quantizations on the Hub n/a — API-only n/a — API-only
Gated n/a — API-only n/a — API-only
First seen on the Hub n/a — API-only n/a — API-only
API input price / 1M tokens $0.30 $0.25
API output price / 1M tokens $2.50 $1.50
Est. cost per 1M input + 1M output tokens $2.80 $1.75
Cached input / 1M tokens $0.03 $0.025
AA Intelligence Index 15.5 —
AA Coding Index — —
AA Agentic Index — —
Max output tokens 65,535 65,536
API providers 1 2
Tool calling Yes Yes
Reasoning mode Yes Yes

API cost

Estimated cost of 1M input + 1M output tokens via OpenRouter

Gemini 2.5 Flash $2.80
Gemini 3.1 Flash Lite $1.75

Gemini 3.1 Flash Lite is 1.6× cheaper at list price.

Adjacent comparisons