OpenAI's AI beats every human at AtCoder, a top competitive programming contest

At the AtCoder World Tour Finals 2026, an OpenAI system crushed all human competitors in an exhibition match, solving all five problems in the Algorithm Division. Two of those problems were rated exceptionally difficult by observers.

The annual competition brings the world's best competitive programmers to Japan. As part of the OpenAI-sponsored event, an exhibition match pitted an OpenAI AI agent against the human finalists in a "Human vs. AI" format. A "Humanity Prevails Award" of 600,000 yen was offered to any participant who could both beat the AI and finish first.

The problems were unusually tough. Competitive programmer Psyho (FakePsyho) explained on X that AtCoder's onsite Algorithm track is known for problems that are extremely thinking-heavy and relatively easy to implement. This contest included two problems, D and E, that were unusually hard even by AtCoder standards.

Two problems stumped the AI for hours

Unlike earlier runs, things didn't go smoothly the whole way through. Psyho documented the progress on X. Two hours in, problems D and E remained unsolved despite multiple attempts, and no human competitor had solved more than one problem. OpenAI's system finally cracked problem D after about three hours. According to Psyho, the AI has moved past the stage where it either quickly finds a correct solution or is completely helpless. By the end, all five problems were solved, and OpenAI's system sat in first place by a wide margin.

Borys Minaiev, an ICPC world champion who works on reasoning models at OpenAI, commented during the Algorithm Division livestream that the result was actually pretty unexpected. He had expected the system to solve everything, but said problems D and E were significantly harder than any AtCoder problem the team had seen before. In tests on earlier competitions, the system typically solved everything in under an hour, similar to how it handled problems A, B, and C this time.

On the system's architecture, Minaiev said it consists of a model with a small harness to scale compute at test time. The model itself is comparable to GPT-5.6, which ships this Thursday. The system had no internet access. Six months ago, Minaiev said, they wouldn't have been able to solve most of these problems.

Shortly after he left the stream, OpenAI's system solved the final problem E.

AI wins 5 to 3

About a year ago, an OpenAI AI placed second at the AtCoder Heuristics World Finals 2025. That model ran for ten hours fully autonomously under the same conditions as the human finalists. It lost its early lead midway through and was eventually overtaken by FakePsyho. OpenAI called it the first known top-three finish by an AI model at a leading programming and math competition.

This time, OpenAI's model took first place with 8,300 points and five solved problems. Runner-up tour1st scored 4,300 points. No human competitor solved problems C or E.

The latest step in a rapid climb

The result fits a pattern that's been building for a while. At the International Olympiad in Informatics (IOI) 2025, an OpenAI system scored at gold medal level. OpenAI researcher Sheryl Hsu said the system ranked sixth, ahead of all but five of the 330 human participants. The jump over a single year stands out: in 2024, OpenAI's system narrowly missed a bronze medal and placed in the 49th percentile. A year later, it climbed to the 98th percentile. At the 2025 ICPC World Finals, OpenAI's system solved all twelve problems and would have taken first place, while Google's Gemini 2.5 Deep Think reached gold level.

In all of these runs, OpenAI has stressed that the systems weren't trained specifically for each competition. At the ICPC, for example, the setup was an ensemble of general reasoning models. GPT-5 solved eleven of the twelve problems, and an experimental model cracked the hardest final problem after nine submissions, something no human team managed.

The company's next target is likely the International Olympiad in Informatics 2026 in early August.