Project Euler
Maths problems you crack with code — an endless, free ladder that builds real problem-solving.
- Computer Science
- Natural Sciences
- Who can enter
- Anyone worldwide — free; no deadline, work at your own pace
- What it costs
- Free — an account is all you need, and there is no paid tier.
- When it closes
- We could not confirm this year's date against the organiser's own page, so we are not showing a countdown for it. Last published: Self-paced — hundreds of problems, solve any time, no registration.
Sending this to someone sends the four facts above, not just a name — they will see who can enter and what it costs before they decide.