OpenOlympiad
Free · No ads · Open to everyone

Free olympiad practice that started as a dad's HTML file.

OpenOlympiad is a growing free practice library for IMO, NSO, iOM, and iOS olympiad prep — built by a parent, refined by teachers, used by hundreds of students. The whole thing stays free.

The catalog is growing.

42
chapters across Math + Science
1,500+
practice questions, four difficulty tiers each chapter
4
olympiad patterns: IMO · iOM · NSO · iOS

And it's growing — every week we add new questions, refine explanations, and extend coverage. Teachers can contribute directly (more on that below).

Teachers

Contribute questions. Earn badges. Keep your students drilling.

Sign up with your school email. Add questions to topics you teach. Hit milestones and get contributor badges visible on your profile. Your students see fresh material every week.

🏅 Contributor milestones

  • 🥉 First question contributed → Bronze
  • 🥈 25 questions → Silver
  • 🥇 100 questions → Gold
  • 🚀 250 questions → Platinum
  • 🏆 500 questions → Founder's Circle
Be the first contributor — sign up as a teacher and submit a question.

🏫 How school whitelisting works

  1. One teacher signs up with their school email.
  2. The school's domain is auto-claimed; they become the school admin.
  3. Other teachers from the same domain auto-join.
  4. Teachers create groups, share invite links, monitor progress.

Want to onboard officially? Use the contact form so we know you're coming and can help with first-week setup.

Schools

Get your school onboarded.

Any teacher with your school's email domain can claim the school. From there, invites flow downhill: teachers add their classes, students join via link, and you get a unified view of who's practicing what.

?
Stuck somewhere?

The yellow help button.

Imagine: it's 9pm. You're on Question 7. The answer feels wrong. You squint. Yes — definitely wrong.

Down in the corner, a friendly yellow ? is waiting. Tap it. Type a sentence: “The answer to Q7 of fractions-basic looks wrong.” Hit send.

Across town, the dad-who-built-this gets a ping. He reads it. He fixes it. Sometimes before you wake up. Every page has the button. Every message gets read.

👀
1. Spot the ❔
Bottom-right of every page once you're signed in.
✏️
2. One sentence
Tell us what looked off — bug, wrong answer, anything.
📨
3. We read it
Real human, usually within a day. No ticket queues.
Made by parents and teachers, for students. Built nights and weekends with Claude Code. Open-access. No paywall.