The 29th International Obfuscated C Code Contest (IOCCC) 2025 Winners
See below for links to the 2025 winning IOCCC entries .
Check out the index.html web pages for each winning entry. They have most of the information you need to compile and run the winning program. Take a look at the winning source code and try to figure out how it works. You might also want to check out the author’s remarks for even more details.
You may download all winning entries in the form of a compressed tarball for this year’s contest.
For IOCCC29 , the volume and quality of submissions were at near-historic heights.
IOCCC28 was speculated to have attracted a record number of submissions due to the 4-year absence, allowing authors to refine their submissions, resulting in a higher-than-usual submission quality.
IOCCC29 was the second consecutive contest after the 2020-2024 hiatus. And yet, the number of submissions for IOCCC29 was similar to last year’s contest, and the overall submission quality remained high for this contest. So perhaps the increased submission volume, combined with a higher-than-usual submission quality, is due to factors such as improved website design, increased social media presence, authors building on the ideas of past winning entries, and other factors?