No. 5 of 33 ·Automated Grading Software

DMOJ

Web · Windows · Linux · Self-hosted · API

Freedom report

Three barsScore 6.5

Free tierA free tier is on its own pricing page
Open codeNo open-source code on record
Runs widely3 of 6 device platforms
DocumentedPlans, terms and facts published

DMOJ is ranked #5 of 33 in automated grading software on Freedom251. It runs on API, Linux, Self-hosted, Web, Windows. There is a free plan.

DMOJ plans and pricing

All plans

Public contest hosting Free Public contests hosted on DMOJ dmoj.ca · 4 Oct 2026

Private contest hosting Not published For educational organizations; small fee, amount not stated dmoj.ca · 4 Oct 2026

Compared on automated grading software

Programming autograding: Yes

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The record

Purpose: DMOJ is a modern contest platform and archive of programming problems, and is entirely open source.
Problem archive: The site hosts problems from past CCC, CCO, COCI, IOI, and JOI competitions, as well as other sources.
Contests: DMOJ runs the DMOJ Monthly Open Programming Competition for people interested in competitive programming.
Judging: The platform supports interactive and signature-graded tasks, runtime data generators, custom output validators, per-language resource limits, and scaling to hundreds of judging servers.
Contest formats: The contest system supports ICPC, IOI, AtCoder, and ECOO formats, along with system testing, hidden scoreboards, and virtual participation.
Plagiarism integration: The contest system integrates with Stanford MOSS for plagiarism checking.
Problem statements: Problem statements support Markdown, LaTeX math and figures, syntax highlighting, PDF generation, and built-in editorials.
Authentication and access: The platform supports OAuth login with Google, Facebook, and GitHub, two-factor authentication, and fine-grained staff permissions.
Security reporting: DMOJ asks researchers to send potential security issues privately for responsible disclosure before making them public.
Support: The site asks users with questions about hosting contests to contact a moderator.
Self-hosting: The maker provides documentation for installing the DMOJ site and judge.
Self-hosting requirement: The installation guide says the site is tested to work with MySQL and is unlikely to work with other databases.
Use restrictions: DMOJ says AI use is prohibited in rated contests and use of its judging resources for AI training is prohibited.
Audience: DMOJ offers free public contest hosting and says educational organizations can contact it about hosting private contests for a small fee.
Price from: Free

Where it ranks on Freedom251

Best Automated Grading Software in 2026#5 of 33
Best Coding Challenge Platforms in 2026#2 of 30

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Sources

dmoj.ca/about/· checked 4 Oct 2026
github.com/DMOJ/online-judge· checked 4 Oct 2026
dmoj.ca/security/· checked 4 Oct 2026
github.com/DMOJ/docs· checked 4 Oct 2026
github.com/DMOJ/docs/blob/master/docs/site/install· checked 4 Oct 2026
dmoj.ca/post/292-dmoj-ai-policy· checked 4 Oct 2026