Coming soon

Due to COVID-19, IOI 2021 will be hosted by Singapore online. Visit the official website to learn more.

Coming soon   IOI will take place online

COCI 2020/2021

Over the next six months we will organize seven online contests as a warm-up for the 2021 season of high school programming competitions. Everyone is welcome to participate! Each contest will be three hours long and will feature five tasks. 

The contestants will also have full feedback with at most 50 submissions per task. The tasks will be of widely varying difficulty; we hope that many beginner or up-and-coming contestants will participate, as well as the more experienced ones.

The first contest will be held this Saturday, October 17, starting at 14:00 (GMT/UTC).
You may use Python, Pascal, C/C++ or Java as your programming language of choice.

The contest will also be featured on a newly-developed judging system. If your students wish to get a bit more familiar with the system, we have uploaded the last 14 COCI seasons for them to practice on. Most problems (except for the very easy ones) have English translations.

The two relevant websites are: - information about the contest - judging system

We hope that you will join us or encourage your students to do so!

This is the fifteenth year in a row that we are hosting the COCI series. You can find the tasks (statements, test data and solutions) from the previous years at There are over 600 original tasks for students to practice on!

With regards,
Kresimir Malnar
Croatian Computer Science Association

Need more info?


Not sure where to go? Click here to view some basic information on how to learn programming and prepare to win a medal at the IOI.


A couple of volunteers maintain a separate page with stats about people who participated at the International Olympiad in Informatics.


The IOI publishes a journal every year, with original high-quality scientific papers related to education, contests and algorithms.