Project Euler
Project Euler is a web-based collection of mathematical and computer programming problems, presented as recreational exercises.
What Project Euler is
Project Euler is a web-based collection of mathematical and computer programming problems, presented as recreational exercises. Most challenges call for a computer and programming skills, and the site’s stated aim is to help people explore unfamiliar areas and learn new concepts. Its audience includes students, adults interested in mathematics, and professionals who want to keep their problem-solving and mathematics skills current. The archive lists problems 1 through 1003, and a separate recent page shows the ten latest additions. Upcoming release dates and times appear on the News page. Solving problems is free; an account and enabled cookies are needed to track progress. Members can form closed groups with ranked tables showing progress and solve times. Friends and group members can view a member’s progress page even when the public profile is hidden. Accounts use usernames and passwords without real names, email addresses, or IP addresses. Since accounts lack verifiable personal information, a lost password cannot be recovered, though members can generate an emergency recovery key.
Good
- Free registration and web access
- Archive lists problems 1 through 1003
- Closed groups include ranked progress tables
- Upcoming release dates appear on the News page
Watch out
- Progress tracking requires an account and cookies
- Lost passwords cannot be recovered
- Friends and group members can see hidden-profile progress
Who it suits
It suits students, math-interested adults, and professionals looking for recreational programming and mathematics challenges. Progress tracking and group tables are useful for members who want to follow their solving activity.
Verdict
Project Euler offers a large archive of recreational math and programming problems, with free accounts for progress tracking and group features. Be aware that tracking requires cookies and lost passwords cannot be recovered.
Plans and prices
From Project Euler's own pricing page, checked 9 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| Free | Free | Free registration · account required to track progress |
The facts
Each one read from Project Euler's own pages, with the date it was checked.
What it does
- Account recovery
- Because accounts have no verifiable personal information, the site cannot recover an account if its password is lost; members can generate an emergency recovery key.checked 9 Oct 2026
- Audience
- The problems are aimed at students, adults interested in mathematics, and professionals who want to keep their problem-solving and mathematics skills current.checked 9 Oct 2026
- Community groups
- Groups let members create closed communities with ranked tables showing members’ progress and when they solved each problem.checked 9 Oct 2026
- Data collection
- The privacy policy says accounts do not require or store real names, email addresses, or IP addresses; accounts use usernames and passwords.checked 9 Oct 2026
- Data sharing
- Project Euler says it does not share database information with third parties.checked 9 Oct 2026
- Group visibility
- Friends and group members can see a member’s progress page even when that member has hidden their public profile.checked 9 Oct 2026
- Problem archive
- The archive lists problems 1 through 1003, and the recent page shows the ten most recently published problems.checked 9 Oct 2026
- Problem-solving policy
- The site says solve times are automatically processed and profiles with unrealistic solve patterns may be flagged for review and marked untrusted.checked 9 Oct 2026
- Progress tracking
- Tracking progress requires an account and cookies enabled; registration is free.checked 9 Oct 2026
- Purpose
- The site aims to help people explore unfamiliar areas and learn new concepts in a fun, recreational context.checked 9 Oct 2026
- Release schedule
- The site publishes upcoming problem release dates and times on its News page.checked 9 Oct 2026
- Security
- The site says connections use HTTPS and that passwords and account recovery keys are hashed using PHP’s one-way password hashing algorithm.checked 9 Oct 2026
- Support
- Privacy or security concerns can be sent to [email protected]; other queries are directed to the alternative forum.checked 9 Oct 2026
- What it is
- Project Euler is a series of challenging mathematical and computer programming problems, most of which require a computer and programming skills to solve.checked 9 Oct 2026
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