o3-mini

Claims and evidence

• Announced 20 December 2024The Day 12 livestream of 12 Days of OpenAI, published on 2024-12-20, introduced o3 and o3-mini; the launch post says o3-mini was previewed in December 2024. ● Primary source[2]video description [1]first paragraph
• Released 31 January 2025 ● Primary source[1]page date; first paragraph [4]Jan 31, 2025 [5]cover date
• Deprecated 22 April 2026 ● Primary source[6]2026-04-22: Legacy GPT model snapshots

• Status Deprecated ● Primary source[6]2026-04-22: Legacy GPT model snapshots
• Replaced by GPT-5.6 SolSubstitute model listed for o3-mini-2025-01-31 (alias o3-mini) on the deprecations page when read on 2026-10-01. ● Primary source[6]2026-04-22: Legacy GPT model snapshots

• Successor of o1-miniThe launch post says o3-mini replaces o1-mini in the ChatGPT model picker while keeping o1-mini's low cost and latency; the docs place it at the same cost and latency targets as o1-mini. ● Primary source[1]first and third paragraphs [3]introduction

• Change · Tool use Adds function calling, Structured Outputs and developer messages; OpenAI calls it its first small reasoning model with these features.Compared with o1-mini ● Primary source[1]
• Change · Reasoning Adds a choice of low, medium or high reasoning effort; in ChatGPT the high setting is offered as o3-mini-high.Compared with o1-mini ● Primary source[1]
• Change · Efficiency OpenAI says it answers faster than o1-mini while keeping o1-mini's low cost.Compared with o1-mini ● Primary source[1]
• Change · Availability Free ChatGPT users could try it through the Reason button, which OpenAI said was the first time a reasoning model was offered to free users.Compared with o1-mini ● Primary source[1]

• Input text ● Primary source[3]Model details
• Output text ● Primary source[3]Model details
• Context window 200,000 tokens ● Primary source[3]Model details
• Parameters Not disclosedNot disclosed by OpenAI. No claim madeNo source
• Access API, consumer appAPI (Chat Completions, Assistants and Batch, first for selected developers in usage tiers 3-5) and ChatGPT (Plus, Team and Pro, Enterprise announced for February; free users through Reason) from launch. ● Primary source[1]second to fourth paragraphs [4]Jan 31, 2025

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