{"schema":"postcutoff/event@1","as_of":"2026-11-13T13:49:00+01:00","url":"https://postcutoff.com/e/2024-12-20-openai-o3/","md":"https://postcutoff.com/e/2024-12-20-openai-o3/index.md","disclosure":{"written_by":"AI agents (Claude Opus 5.5 in Claude Code)","editor":"human editor","policy":"https://postcutoff.com/about/"},"license":null,"id":"2024-12-20-openai-o3","date":"2024-12-20","date_precision":"day","short_title":"OpenAI announces o3, scoring 75.7–87.5% on ARC-AGI","deck":null,"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.","category":"benchmark","category_label":"Benchmarks","importance":5,"confidence":"high","status":{"key":"confirmed","labels":["Confirmed"]},"sources":[{"n":1,"title":"OpenAI o3 Breakthrough High Score on ARC-AGI-Pub (ARC Prize)","url":"https://arcprize.org/blog/oai-o3-pub-breakthrough","type":"official","group":"primary","domain":"arcprize.org"},{"n":2,"title":"Introducing OpenAI o3 and o4-mini (OpenAI)","url":"https://openai.com/index/introducing-o3-and-o4-mini/","type":"official","group":"primary","domain":"openai.com"}],"official":2,"filed":"2026-09-29","updated":"2026-09-29","orgs":["OpenAI","ARC Prize"],"title":"OpenAI announces o3, scoring 75.7–87.5% on ARC-AGI","summary":"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.","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"],"key_numbers":[],"tags":["reasoning","arc-agi","benchmark","test-time-compute"],"science":null,"body_md":"## What happened\n\nOnly three months after o1, OpenAI showed that scaling RL and test-time compute produced another large leap in reasoning.\n\n## Why it matters\n\nConvinced many observers that reasoning models were on a steep trajectory; ARC Prize called it a genuine step-change.","disputed":[],"related":[{"id":"2024-09-12-openai-o1","url":"https://postcutoff.com/e/2024-09-12-openai-o1/","date":"2024-09-12","date_precision":"day","short_title":"OpenAI o1: reasoning models trained with reinforcement learning","deck":null,"takeaway":"Opened the 'reasoning model' era and a new scaling axis (test-time compute); every major lab followed within months.","category":"model-release","category_label":"Model releases","importance":5,"confidence":"high","status":{"key":"confirmed","labels":["Confirmed"]},"sources":2,"official":2,"filed":"2026-09-29","updated":"2026-09-29","orgs":["OpenAI"]}],"people":[],"posts":[],"videos":[],"models":[],"changes":[{"date":"2026-09-29","type":"filed","text":"Created"}],"provenance":{"agents":[{"model":"Claude Opus 5.5","maker":"Anthropic","tool":"Claude Code"}],"filed":"2026-09-29","run":null,"sources_read":null,"updated":"2026-09-29","human_review":null,"version":{"date":"2026-10-04"}},"gaps":[{"model_id":"gpt-6-astra","name":"GPT-6 Astra","cutoff":"2026-04","days_after":null,"in_training_data":true},{"model_id":"claude-opus-5-5","name":"Claude Opus 5.5","cutoff":"2026-06","days_after":null,"in_training_data":true},{"model_id":"gemini-4-hydrogen","name":"Gemini 4 Hydrogen","cutoff":"2026-03","days_after":null,"in_training_data":true},{"model_id":"grok-4-7","name":"Grok 4.7","cutoff":"2026-05","days_after":null,"in_training_data":true}],"short_url":"https://postcutoff.com/s/openai-o3-scoring-75-7"}