International Obfuscated C Code Contest

International Obfuscated C Code Contest
The logo of the IOCCC
StatusActive
GenreCoding contest
FrequencySemi-annually
Years active1984–1996, 1998, 2000, 2001, 2004–2006, 2011–2015, 2018–2020, 2024
Inaugurated1984 (1984)
FoundersLandon Curt Noll, Larry Bassel
Most recent2024
Next eventDec 2025
Websitewww.ioccc.org

The International Obfuscated C Code Contest (abbreviated IOCCC) is a computer programming contest for code written in C that is the most creatively obfuscated and held annually (when possible). It is described as "celebrating C's syntactical opaqueness". The winning code for the 28th contest, held in 2024/25, was announced by live stream 2 Aug 2025 in addition video segments for each of the 23 winners.

Entries are evaluated anonymously by the current sitting judges, Leonid A. Broukhis & Landon Curt Noll. The judging process is documented in the competition FAQ and consists of elimination rounds. By tradition, no information is given about the total number of entries for each competition. Winning entries are awarded with a category, such as "Worst Abuse of the C preprocessor" or "Most Erratic Behavior", and then announced on the official IOCCC website. The contest states that being announced on the IOCCC website is the reward for winning (plus bragging rights).

Previous contests were held in the years 1984–1996, 1998, 2000, 2001, 2004–2006, 2011–2015, 2018–2020, and 2024.