What is NACLO?

NACLO is a contest in which high-school students solve linguistic problems. In solving these problems, students learn about the diversity and consistency of language, while exercising logic skills. No prior knowledge of linguistics or second languages is necessary. Professionals in linguistics, computational linguistics and language technologies use dozens of languages to create engaging problems that represent cutting edge issues in their fields. The competition has attracted top students to study and work in those same fields. It is truly an opportunity for young people to experience a taste of natural-language processing in the 21st century.

Announcements

February 8, 2026The 2026 NACLO Open Round was held on January 29, 2026. We are currently grading the contests. We will share the results release date once grading is closer to completion; in the meantime, we ask that students verify that their booklet is in the list of uploaded booklets. Thank you for your patience.
January 27, 2026Registration for students is now closed. All remaining unregistered students must register as walk-ins. For walk-ins, registration will reopen early on the day of the contest, January 29. Walk-in students should arrive early to complete registration on the website and receive a NACLO ID number. A NACLO ID is required in order to participate in the contest, so students who arrive late may not be able to compete. Note that not all sites support walk-ins.
January 14, 2026Registration is closing soon. The site registration deadline is January 22, and the student registration deadline is January 26.
Students should confirm that they can successfully log in to their account on the registration system and that they are registered with a site. Please note that students who are not signed up for a site will not be able to participate in the contest.
For full details on contest procedures, rules, and expectations, please review the 2026 Student Handbook and the 2026 Coordinator Handbook.
October 24, 2025Registration for students is now open. Note that not all expected sites have signed up yet. You may register without a site for now, but be aware that you will need to find and select a site later (before the contest) in order to participate. NACLO does not find a site for you. Please read the 2026 Student Handbook for more information. We also invite all students to join the NACLO Discord.
October 20, 2025Registration for site hosts opened on October 20. Past hosts will need to re-register their site.
September 19, 2025The 2026 NACLO Open Round will be held on Thursday, January 29th, and the Invitational Round will be held on March 19th. We are working on changes to streamline the registration process.

Please Donate

You can help support NACLO either by mailing a check or giving online. For more information on both, please see our donations page. We thank you for your support!

Current Sponsors of NACLO

Here are those organisations that have been kind enough to sponsor NACLO. If your organisation would like to sponsor then read our information on donation.