o3 Pro vs GPT-5.2 Pro

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

openai · A · API-only
Input / 1M
$20.00
Output / 1M
$80.00
AA index
21.9
proprietary · 200K context
openai · B · API-only
Input / 1M
$21.00
Output / 1M
$168.00
AA index
—
proprietary · 400K context

Specification comparison

Differences are highlighted; identical values are muted.

Specification o3 Pro GPT-5.2 Pro
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 200,000 400,000
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 $20.00 $21.00
API output price / 1M tokens $80.00 $168.00
Est. cost per 1M input + 1M output tokens $100.00 $189.00
Cached input / 1M tokens — —
AA Intelligence Index 21.9 —
AA Coding Index — —
AA Agentic Index — —
Max output tokens 100,000 128,000
API providers 1 1
Tool calling Yes Yes
Reasoning mode Yes Yes

API cost

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

o3 Pro $100.00
GPT-5.2 Pro $189.00

o3 Pro is 1.9× cheaper at list price.

Adjacent comparisons