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Free resources for DSA practice

~7 min

In short

  • Pick one practice sheet or roadmap and one problem site, and stick with them for the first pass.
  • Check the free and paid status on each site yourself. Several pages do not state it clearly, and terms can change.
  • The sites below were checked to load on 18 Oct 2026. Most could not be read in full by the author, so treat the notes as a starting point.

Study plans and sheets

Tech Interview Handbook: coding interview study plan. A structured plan with about 75 questions, weeks 1 to 4 for topic study and weeks 5 to 12 for practice. Good if you want a plan rather than a list. The plan is one author's suggestion, not a company statement. The site is at https://www.techinterviewhandbook.org/coding-interview-study-plan/.

Striver's A2Z DSA sheet. The sheet page lists about 400 or more practice problems and about 50 theory lessons; its header says 495 topics. Free users get a limited number of practice questions and limited video solutions, and the premium plan unlocks the rest. Good if you want a long sheet with video explanations for some problems. Check the page for the current free limit before you commit. Link: https://takeuforward.org/strivers-a2z-dsa-course/strivers-a2z-dsa-course-sheet-2/

NeetCode. The practice and roadmap pages load (https://neetcode.io/practice and https://neetcode.io/roadmap). The page text does not show which lists are free, so check on the site which parts you can use without paying. Good for a shorter list, if the free part covers what you need.

Coding interview university (GitHub). A community-written study plan covering DSA and other topics. Content was not read by the author; check the repository before you rely on it. Link: https://github.com/jwasham/coding-interview-university

Problem sites

CSES Problem Set. 18 sections and 400 problems, organised by section. The page offers login or account creation, but it does not state whether the set is free. Check that yourself before you plan around it. Link: https://cses.fi/problemset/

Codeforces. A competitive programming site with practice problems and rated contests. The author's tool could not load the site, so check it in a browser. Its rating system is covered in contests and ratings. Link: https://codeforces.com/

LeetCode. A widely used interview practice site with a large problem list. The author's tool could not load it, so check the current free and premium split in a browser. Link: https://leetcode.com/

GeeksforGeeks. Has practice problems, a Problem of the Day, tutorials and an interview section. It also sells paid courses. The page does not label which content is free, so check each section. Link: https://www.geeksforgeeks.org/

HackerRank, Algorithms domain. A practice domain with algorithm problems. The root site returned an error to the author's tool, but the Algorithms page loaded. Link: https://www.hackerrank.com/domains/algorithms

Competitive programming references

USACO Guide. A guide aimed at competitive programmers. Content was not read by the author; check it for the level you need. Link: https://usaco.guide/

cp-algorithms. A reference site for competitive programming algorithms. Content was not read by the author. Link: https://cp-algorithms.com/

AtCoder and CodeChef. Both run contests and have archives. The contest pages load; the author did not read the content or check the free status. Links: https://atcoder.jp/contests/ and https://www.codechef.com/contests

Mock interviews

Pramp and interviewing.io are both listed as live. Whether their mock interviews are free, and on what terms, was not verified. Check the current terms before you plan on them. Links: https://www.pramp.com/ and https://www.interviewing.io/mocks

Try this

Choose one sheet or plan and one problem site from this page. Write the first five problems of the sheet in your practice log, and check on the site whether each one is free to open without paying.

Sources

  • Tech Interview Handbook: https://www.techinterviewhandbook.org/coding-interview-study-plan/
  • Striver's A2Z DSA sheet: https://takeuforward.org/strivers-a2z-dsa-course/strivers-a2z-dsa-course-sheet-2/
  • NeetCode practice: https://neetcode.io/practice
  • Coding interview university: https://github.com/jwasham/coding-interview-university
  • CSES Problem Set: https://cses.fi/problemset/
  • Codeforces: https://codeforces.com/
  • LeetCode: https://leetcode.com/
  • GeeksforGeeks: https://www.geeksforgeeks.org/
  • HackerRank Algorithms: https://www.hackerrank.com/domains/algorithms
  • USACO Guide: https://usaco.guide/
  • cp-algorithms: https://cp-algorithms.com/
  • AtCoder contests: https://atcoder.jp/contests/
  • CodeChef contests: https://www.codechef.com/contests
  • Pramp: https://www.pramp.com/
  • interviewing.io mocks: https://www.interviewing.io/mocks