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Project Euler

Hacker Approved

Ranked 2 of 8 coding practice platforms by recommenders

Recommended for math-and-code puzzles that reward deep thinking and show how others solved them. Caveat: later problems need heavy math, and explanations are thin.

Recommended for math-and-code puzzles that reward deep thinking and show how others solved them. Caveat: later problems need heavy math, and explanations are thin.

51 people gave an opinion

recommend it
45
criticize it
6
approval share
88%
Each figure is one person. RecommendsCriticizes

Recommended in 5 of 13 months

  1. November 2025: recommended
  2. December 2025: recommended
  3. January 2026: not recommended
  4. February 2026: recommended
  5. March 2026: not recommended
  6. April 2026: not recommended
  7. May 2026: not recommended
  8. June 2026: recommended
  9. July 2026: not recommended
  10. August 2026: recommended
  11. September 2026: not recommended
  12. October 2026: not recommended
  13. November 2026: not recommended (month in progress)

Owned for 12 years

Median of the 9 owners who said how long they have had it.

Each square is one year.

Why it carries the badge

  • 45 people recommend itNeeds 10 or more, met.
  • 7.5 recommenders for every criticNeeds 2 to 1 or better, met.
  • Recommended in 5 of 13 monthsNeeds 4 or more, met.

The same three rules apply to every product, and the badge can’t be bought. How the badge works

What people say about it

The reasons people give, with the number of comments that give each one. Open a reason to read what they said.

Why people recommend it

Each mark is one comment

  • Sparked love of programming

    “Project Euler was foundational in my education and growth as a programmer.”

    Comment from 12 Nov 2025 in “Project Euler”

    “I too owe had my love for programming captured through project Euler”

    Comment from 12 Nov 2025 in “Project Euler”

    “Project Euler spurred my love for math and programming when I was 15”

    Comment from 13 Nov 2025 in “Project Euler”
  • More fun than LeetCode-style problems

    “These are both a lot more fun, and a lot more educational than leetcode problems.”

    Comment from 12 Nov 2025 in “Project Euler”

    “Solving these were more fun than any other programming problems site I've seen.”

    Comment from 12 Nov 2025 in “Project Euler”

    “So much more fun than leetcode. OTOH, unlikely to help you in an interview.”

    Comment from 12 Nov 2025 in “Project Euler”
  • Compact problems that reward deep thinking

    “most of the problems are so compact that you can just read about the full problem, then spend hours and days thinking about possible solutions”

    Comment from 12 Nov 2025 in “Project Euler”

    “I'm so happy to have spent twenty years of my life learning math and solving problems on Project Euler”

    Comment from 12 Nov 2025 in “Project Euler”

    “Thousand of hours on this. Love it.”

    Comment from 13 Nov 2025 in “Project Euler”
  • Seeing others' solutions and strategies

    “The biggest thing I learned from PE was that neither elegant theory nor brute force had a monopoly on successful optimization strategies.”

    Comment from 12 Nov 2025 in “Project Euler”

    “The most fun on this site is solving a problem and then having your mind blown by solutions”

    Comment from 12 Nov 2025 in “Project Euler”

    “You get to see not just how you solved the problem, but how others saw and tackled it.”

    Comment from 13 Nov 2025 in “Project Euler”

What people warn about

Each mark is one comment

  • Too much math, little programming

    “after that they take more and more time and require deeper mathematical knowledge”

    Comment from 13 Nov 2025 in “Project Euler”

    “I ended up solving most of them with math and so little programming.”

    Comment from 23 Jun 2026 in “My Mathematical Regression”

    “half the problems can be optimized to return 5 # because math”

    Comment from 23 Jun 2026 in “My Mathematical Regression”
  • Little explanation or hints given

    “the algorithms given are not explained in detail, so the learning experience is somewhat mediocre”

    Comment from 23 May 2026 in “Fast Factorial Algorithms”

    “there are no hints or information on how to approach the problem”

    Comment from 12 Nov 2025 in “Project Euler”
  • Accounts deleted or data lost

    “I remember there were data loss, but my account appears to have been recovered.”

    Comment from 12 Nov 2025 in “Project Euler”

    “No one tells you that they delete inactive accounts.”

    Comment from 12 Nov 2025 in “Project Euler”

Other coding practice platforms people recommend

The four most recommended other coding practice platforms, with the same counts for each, so you can compare like for like. The tick on each bar marks the 2 to 1 line the badge needs.

Project Euler compared with 4 alternatives
ProductRecommendCriticizeApprovalMonthsOwnedBadge
LeetCode506344%11——
Project EulerThis page45688%512 yrs9 ownersApproved
Advent of Code31586%64 yrs3 ownersApproved
Codecrafters14382%4—Approved
AlgoDrill131252%1——
See all 8 coding practice platforms, ranked

What people said

40 of the 52 comments that mention it, newest first. Each links to the original comment.

“I did some Project Euler, which was the cooler predecessor. It was a fun”

MixedComment from 22 Aug 2026 in “A formal degree and algorithmic problem-solving is the answer. Always has been”

“I ended up solving most of them with math and so little programming.”

CriticizesComment from 23 Jun 2026 in “My Mathematical Regression”

“half the problems can be optimized to return 5 # because math”

CriticizesComment from 23 Jun 2026 in “My Mathematical Regression”

“the algorithms given are not explained in detail, so the learning experience is somewhat mediocre”

CriticizesComment from 23 May 2026 in “Fast Factorial Algorithms”

“there are plenty interesting enough questions which it at least helps”

RecommendsComment from 4 Feb 2026 in “I Miss Thinking Hard”

“Find problems to solve with code, and write code to solve those problems.”

RecommendsComment from 13 Dec 2025 in “What is the most effective way to learn programming?”

“I have only had some previous experience with Project Euler, which I liked for the loop of”

RecommendsComment from 21 Nov 2025 in “FAWK: LLMs can write a language interpreter”

“You get to see not just how you solved the problem, but how others saw and tackled it.”

RecommendsComment from 13 Nov 2025 in “Project Euler”

“I spent a lot of time on it, and learned a considerable amount of theory and hacks.”

RecommendsComment from 13 Nov 2025 in “Project Euler”

“after that they take more and more time and require deeper mathematical knowledge”

MixedComment from 13 Nov 2025 in “Project Euler”

“Imagine the relief I felt when both of these questions where from the ones that I solved on Project Euler”

RecommendsComment from 13 Nov 2025 in “Project Euler”

“Thousand of hours on this. Love it.”

RecommendsComment from 13 Nov 2025 in “Project Euler”

“Project Euler spurred my love for math and programming when I was 15”

RecommendsComment from 13 Nov 2025 in “Project Euler”

“The leetcode before leetcode. Hail.”

RecommendsComment from 13 Nov 2025 in “Project Euler”

“most of the problems are so compact that you can just read about the full problem, then spend hours and days thinking about possible solutions”

RecommendsComment from 12 Nov 2025 in “Project Euler”

“There's an excellent core development team that works with problem-submitters to get problems tuned up for Project Euler.”

RecommendsComment from 12 Nov 2025 in “Project Euler”

“I'm so happy to have spent twenty years of my life learning math and solving problems on Project Euler”

RecommendsComment from 12 Nov 2025 in “Project Euler”

“I remember there were data loss, but my account appears to have been recovered.”

MixedComment from 12 Nov 2025 in “Project Euler”

“The biggest thing I learned from PE was that neither elegant theory nor brute force had a monopoly on successful optimization strategies.”

RecommendsComment from 12 Nov 2025 in “Project Euler”

“So much more fun than leetcode. OTOH, unlikely to help you in an interview.”

MixedComment from 12 Nov 2025 in “Project Euler”

“No one tells you that they delete inactive accounts.”

CriticizesComment from 12 Nov 2025 in “Project Euler”

“I learned so much from this site- including that so much education comes from being prompted to ask the right questions.”

RecommendsComment from 12 Nov 2025 in “Project Euler”

“This was my great procrastination side quest during grad school.”

RecommendsComment from 12 Nov 2025 in “Project Euler”

“it solidified for me my interest in CS but in general abstract thinking and problem solving”

RecommendsComment from 12 Nov 2025 in “Project Euler”

“It was a great way to learn a bit of number theory and regain my interest in programming.”

RecommendsComment from 12 Nov 2025 in “Project Euler”

“Solving these were more fun than any other programming problems site I've seen.”

RecommendsComment from 12 Nov 2025 in “Project Euler”

“These are both a lot more fun, and a lot more educational than leetcode problems.”

RecommendsComment from 12 Nov 2025 in “Project Euler”

“I too owe had my love for programming captured through project Euler”

RecommendsComment from 12 Nov 2025 in “Project Euler”

“a great way to learn a new programming language is to try project Euler problems with it”

RecommendsComment from 12 Nov 2025 in “Project Euler”

“I love running euler problems when trying to learn the basics of a new programming language”

RecommendsComment from 12 Nov 2025 in “Project Euler”

“It was a fun puzzle but you had to be awake at a funky time to do it.”

MixedComment from 12 Nov 2025 in “Project Euler”

“I'm glad to see artifacts from the past like this are still out there on the internet.”

RecommendsComment from 12 Nov 2025 in “Project Euler”

“this is what my professors recommended for training programming skills”

RecommendsComment from 12 Nov 2025 in “Project Euler”

“instilling the playful enjoyment of writing programs in college”

RecommendsComment from 12 Nov 2025 in “Project Euler”

“The most fun on this site is solving a problem and then having your mind blown by solutions”

RecommendsComment from 12 Nov 2025 in “Project Euler”

“I loved how solving a problem unlocks a secret forum only available to other solvers.”

RecommendsComment from 12 Nov 2025 in “Project Euler”

“Project Euler was foundational in my education and growth as a programmer.”

RecommendsComment from 12 Nov 2025 in “Project Euler”

“the website was a big contributor to my love of programming”

RecommendsComment from 12 Nov 2025 in “Project Euler”

“Google + Project Euler was how I learned to code”

RecommendsComment from 12 Nov 2025 in “Project Euler”

“there are no hints or information on how to approach the problem”

CriticizesComment from 12 Nov 2025 in “Project Euler”

Counts come from 1,795,640 Hacker News comments, November 2025 to November 2026. How we count. Report a mistake.