Gemini 2.5 Pro Preview 06-05 vs Gemini 3.1 Pro Preview Custom Tools

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

google · A · API-only

Input / 1M

$1.25

Output / 1M

$10.00

AA index

—

proprietary · 1M context

google · B · API-only

Input / 1M

$2.00

Output / 1M

$12.00

AA index

—

proprietary · 1M context

Specification comparison

Differences are highlighted; identical values are muted.

Specification	Gemini 2.5 Pro Preview 06-05	Gemini 3.1 Pro Preview Custom Tools
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	$1.25	$2.00
API output price / 1M tokens	$10.00	$12.00
Est. cost per 1M input + 1M output tokens	$11.25	$14.00
Cached input / 1M tokens	$0.13	$0.20
AA Intelligence Index	—	—
AA Coding Index	—	—
AA Agentic Index	—	—
Max output tokens	65,536	65,536
API providers	1	1
Tool calling	Yes	Yes
Reasoning mode	Yes	Yes

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

Gemini 2.5 Pro Preview 06-05 $11.25

Gemini 3.1 Pro Preview Custom Tools $14.00

Gemini 2.5 Pro Preview 06-05 is 1.2× cheaper at list price.