Model
o4-mini
o4-mini is the smaller, cheaper reasoning model OpenAI released alongside o3 in April 2025, built on the same approach of drawing on tools such as web browsing and code execution partway through its own reasoning. It was aimed at high-volume use where o3's cost and latency were impractical, and OpenAI's system card reported that neither model reached the "High" risk threshold under its revised preparedness framework.
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Featured in threads
Tracks
- Models & capabilities 3
- Benchmarks & progress 2
- Safety & alignment 1
OpenAI retires GPT-4o and other older models from ChatGPT
OpenAI said only about 0.1% of ChatGPT users still chose GPT-4o daily, more than a year after briefly restoring it to Plus users following the GPT-5 rollout backlash.
Models & capabilities
OpenAI and Apollo Research publish work on detecting and reducing scheming in AI models
OpenAI reported cutting detected covert behaviour in o3 from about 13% to 0.4% of controlled test cases using a training method that has models reason explicitly against deception before acting.
Safety & alignment
ARC Prize compares reasoning models with no clear winner
ARC-AGI-2 remained unsolved by every system tested, and which model looked best depended entirely on whether accuracy or cost per task was prioritised.
Benchmarks & progress
ARC Prize analyses o3 and o4-mini on ARC-AGI
The publicly shipped o3 scored 41-53% on ARC-AGI-1, far below the 76-88% OpenAI's pre-release preview had shown the previous December.
Benchmarks & progress · Models & capabilities
OpenAI releases o3 and o4-mini
The first models to use tools such as web browsing, Python and image cropping mid-reasoning; OpenAI's system card said neither reached the 'High' risk threshold under its newly revised framework.
Models & capabilities