o4 Mini vs Gemini 2.5 Flash

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

openai · A · API-only
Input / 1M
$1.10
Output / 1M
$4.40
AA index
16.7
proprietary · 200K context
google · B · API-only
Input / 1M
$0.30
Output / 1M
$2.50
AA index
15.5
proprietary · 1M context

Specification comparison

Differences are highlighted; identical values are muted.

Specification o4 Mini Gemini 2.5 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 200,000 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 $1.10 $0.30
API output price / 1M tokens $4.40 $2.50
Est. cost per 1M input + 1M output tokens $5.50 $2.80
Cached input / 1M tokens $0.28 $0.03
AA Intelligence Index 16.7 15.5
AA Coding Index — —
AA Agentic Index — —
Max output tokens 100,000 65,535
API providers 1 1
Tool calling Yes Yes
Reasoning mode Yes Yes

API cost

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

o4 Mini $5.50
Gemini 2.5 Flash $2.80

Gemini 2.5 Flash is 2.0× cheaper at list price.

Adjacent comparisons