OpenAI announces o3, scoring 75.7–87.5% on ARC-AGI
Confirmed
Importance: historic (5 of 5)The takeaway
On the last day of its ‘12 Days of OpenAI’, OpenAI previewed o3, which scored 75.7% on the ARC-AGI semi-private set (87.5% with high compute) — a benchmark on which earlier LLMs scored in single digits — and 25.2% on FrontierMath.
Status
- Claim
Confirmed
- Our reporting
- High confidence
- Importance
- Historic (5 of 5)
- Last verified
- 29 September 2026
Your AI and this story
- GPT-6 AstraIn its training data
- Claude Opus 5.5In its training data
- Gemini 4 HydrogenIn its training data
- Grok 4.7In its training data
It happened before the cutoffs of all four assistants, so it can be in their training data.
Key facts
- Announced 20 December 2024
- ARC-AGI-1 semi-private: 75.7% (high-efficiency), 87.5% (high-compute), verified by ARC Prize
- FrontierMath: 25.2% vs. under 2% for previous models, per OpenAI
- o3 and o4-mini released publicly on 16 April 2025, with full tool use
What happened
Only three months after o1, OpenAI showed that scaling RL and test-time compute produced another large leap in reasoning.
Why it matters
Convinced many observers that reasoning models were on a steep trajectory; ARC Prize called it a genuine step-change.
Sources
2 sources from 2 sites. Numbers match the chips in the text.
2 sources: 2 primary
Primary
- OpenAI o3 Breakthrough High Score on ARC-AGI-Pub (ARC Prize)arcprize.org, official
- Introducing OpenAI o3 and o4-mini (OpenAI)openai.com, official
Changes
- Filed