Claude Sonnet 4.6 vs Gemini 3.1 Pro Preview

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

anthropic · A · API-only
Input / 1M
$3.00
Output / 1M
$15.00
AA index
30.1
proprietary · 1M context
google · B · API-only
Input / 1M
$2.00
Output / 1M
$12.00
AA index
29.7
proprietary · 1M context

Specification comparison

Differences are highlighted; identical values are muted.

Specification Claude Sonnet 4.6 Gemini 3.1 Pro Preview
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 1,000,000 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 $3.00 $2.00
API output price / 1M tokens $15.00 $12.00
Est. cost per 1M input + 1M output tokens $18.00 $14.00
Cached input / 1M tokens $0.30 $0.20
AA Intelligence Index 30.1 29.7
AA Coding Index 63 68.8
AA Agentic Index 31.8 8.2
Max output tokens 128,000 65,536
API providers 5 2
Tool calling Yes Yes
Reasoning mode Yes Yes

API cost

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

Claude Sonnet 4.6 $18.00
Gemini 3.1 Pro Preview $14.00

Gemini 3.1 Pro Preview is 1.3× cheaper at list price.

Adjacent comparisons