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OJBench

Paper

Progress Over Time

Interactive timeline showing model performance evolution on OJBench

State-of-the-art frontier
Open
Proprietary

OJBench Leaderboard

9 models
ContextCostLicense
1
Moonshot AI
Moonshot AI
1.0T262K$0.75 / $3.50
21.0T
3
Alibaba Cloud / Qwen Team
Alibaba Cloud / Qwen Team
27B262K$0.30 / $2.40
4
Alibaba Cloud / Qwen Team
Alibaba Cloud / Qwen Team
122B
5
Alibaba Cloud / Qwen Team
Alibaba Cloud / Qwen Team
35B
6
Alibaba Cloud / Qwen Team
Alibaba Cloud / Qwen Team
235B
7
Alibaba Cloud / Qwen Team
Alibaba Cloud / Qwen Team
80B
81.0T
8
Moonshot AI
Moonshot AI
1.0T
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Sub-benchmarks

About this benchmark

What is OJBench?

OJBench is a competition-level code benchmark designed to assess the competitive-level code reasoning abilities of large language models. It comprises 232 programming competition problems from NOI and ICPC, categorized into Easy, Medium, and Hard difficulty levels. The benchmark evaluates models' ability to solve complex competitive programming challenges using Python and C++.

OJBench is a text benchmark evaluating models on reasoning tasks. LLM Stats tracks 9 models on this benchmark, scored on a 0–1 scale. The current average is 0.4, with the leader at 0.6.

Compare leaders on the best AI for reasoning leaderboards.

Current leaders

Kimi K2.6 from Moonshot AI currently leads the OJBench leaderboard with a score of 0.606 across 9 evaluated AI models.

1Kimi K2.6Moonshot AI60.6%
2Kimi K2-Thinking-0905Moonshot AI48.7%
3Qwen3.5-27BAlibaba Cloud / Qwen Team40.1%

Source paper

Title
OJBench: A Competition Level Code Benchmark For Large Language Models
Authors
Zhexu Wang, Yiping Liu, Yejie Wang, Wenyang He, and 8 others
Published
Abstract

Recent advancements in large language models (LLMs) have demonstrated significant progress in math and code reasoning capabilities. However, existing code benchmark are limited in their ability to evaluate the full spectrum of these capabilities, particularly at the competitive level. To bridge this gap, we introduce OJBench, a novel and challenging benchmark designed to assess the competitive-level code reasoning abilities of LLMs. OJBench comprises 232 programming competition problems from NOI and ICPC, providing a more rigorous test of models' reasoning skills. We conducted a comprehensive evaluation using OJBench on 37 models, including both closed-source and open-source models, reasoning-oriented and non-reasoning-oriented models. Our results indicate that even state-of-the-art reasoning-oriented models, such as o4-mini and Gemini-2.5-pro-exp, struggle with highly challenging competition-level problems. This highlights the significant challenges that models face in competitive-level code reasoning.

FAQ

Common questions about the OJBench benchmark and leaderboard.

What is the OJBench benchmark?

OJBench is a competition-level code benchmark designed to assess the competitive-level code reasoning abilities of large language models. It comprises 232 programming competition problems from NOI and ICPC, categorized into Easy, Medium, and Hard difficulty levels. The benchmark evaluates models' ability to solve complex competitive programming challenges using Python and C++.

What is the OJBench leaderboard?

The OJBench leaderboard ranks 9 AI models based on their performance on this benchmark. Currently, Kimi K2.6 by Moonshot AI leads with a score of 0.606. The average score across all models is 0.379.

What is the highest OJBench score?

The highest OJBench score is 0.606, achieved by Kimi K2.6 from Moonshot AI.

How many models are evaluated on OJBench?

9 models have been evaluated on the OJBench benchmark, with 0 verified results and 9 self-reported results.

Where can I find the OJBench paper?

The OJBench paper is available at https://arxiv.org/abs/2506.16395. The paper details the methodology, dataset construction, and evaluation criteria.

What categories does OJBench cover?

OJBench is categorized under reasoning. The benchmark evaluates text models.

Are there variants of OJBench?

Yes. OJBench has 1 related variant: OJBench (C++).

What is the best open-source model on OJBench?

Kimi K2.6 by Moonshot AI is the top-ranked open-source model on OJBench, with a score of 0.606 (rank #1).

Which model offers the best value on OJBench?

Among models scoring within 10% of the leader, Kimi K2.6 from Moonshot AI is the cheapest, at $0.75 per million input tokens with a score of 0.606.

How recent are the OJBench leaderboard results?

The OJBench leaderboard was last updated in August 2026 and currently includes 9 evaluated models.