Gemini 4 Carbon vs Gemini 3.5 Flash

API pricing, benchmark indices and specs — updated 11 November 2026.

google · A · API-only
Input / 1M
$2.00
Output / 1M
$10.00
AA index
60
proprietary · 1M context
google · B · API-only
Input / 1M
$1.50
Output / 1M
$9.00
AA index
—
proprietary · 1M context

Specification comparison

Differences are highlighted; identical values are muted.

Specification Gemini 4 Carbon Gemini 3.5 Flash
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 $2.00 $1.50
API output price / 1M tokens $10.00 $9.00
Est. cost per 1M input + 1M output tokens $12.00 $10.50
Cached input / 1M tokens $0.10 $0.15
AA Intelligence Index 60 —
AA Coding Index — 70.1
AA Agentic Index — 26
Max output tokens 943,718 65,536
API providers 2 2
Tool calling Yes Yes
Reasoning mode Yes Yes

API cost

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

Gemini 4 Carbon $12.00
Gemini 3.5 Flash $10.50

Gemini 3.5 Flash is 1.1× cheaper at list price.

Adjacent comparisons