LeetCode

LeetCode
Website type
Private
Founded7 August 2015
Headquarters
Palo Alto, California
,
US
OwnerLeetcode LLC
FounderWinston Tang
Key peopleHercy Chang (CEO)
IndustrySoftware
Employees264 (2025)
Website

LeetCode is an online platform for software coding interview preparation. The site provides algorithmic problems intended for users to learn and practice programming. Since the company founding in 2015, the LeetCode platform has gained popularity among job seekers in the software industry and coding enthusiasts as a resource for technical interviews and coding competitions. As of 2025, the website has 26.3 million monthly visitors.

History

LeetCode was founded in Silicon Valley in 2015 by Winston Tang. After moving to the US from Malaysia in 2005, Tang founded the company, citing his own experiences working at Amazon and Google as inspiration.

LeetCode expanded its operations to China in 2018, providing Chinese problems, solutions and forums on its Chinese website Likou (Chinese: 力扣; pinyin: Lìkòu). In 2021, LeetCode secured its first round of funding, receiving a $10 million investment from Lightspeed China Partners.

Features

LeetCode offers both free and premium access options. While free users have access to a limited number of questions, premium users gain access to additional questions previously used in interviews at large tech companies. The performance of users' solutions is evaluated based on execution speed and memory usage, and is ranked against other submissions in the LeetCode database.

Additionally, LeetCode provides its users with mock interviews and online assessments. LeetCode hosts weekly and biweekly contests, each having 4 problems. After participating in a contest for the first time, one gets assigned a ranking, which can be found in their profile. LeetCode also provides its users with daily challenges, following UTC, with a lucky draw at the end of each month for those who stayed consistent for the month.

LeetCode supports a wide range of programming languages, including Java, Python, JavaScript, and C. Since September 2024, LeetCode China supports Huawei's Cangjie programming language for all problems.

The platform features forums where users can engage in discussions related to problems, the interview process, and share their interview experiences.

Types of problems

Every question on LeetCode has a particular category or tag. Some of the most common tags include arrays, strings, two pointers, stacks, binary search, sliding windows, linked lists, trees, tries, backtracking, heaps, priority queues, graphs, breadth-first search, depth-first search, dynamic programming, greedy algorithms, bit manipulation, database problems, and math.[better source needed] As of January 2026, LeetCode offers 3816 questions across its three levels of difficulty; with 922 questions categorized as easy, 1922 as medium, and 902 as hard.[better source needed]

See also

References

  1. ↑ LeetCode Employee Directory, Headcount & Staff LeadIQ
  2. 1 2 3 Singer, Natasha (2023-04-05). "For Lower-Income Students, Big Tech Internships Can Be Hard to Get". The New York Times. Retrieved 2023-08-09. To gear up for the assessments, many students practice their skills on LeetCode, a free test prep site that offers coding and algorithmic problems, along with detailed solutions. The site also offers premium services. For $35 a month, it gives members access to specific problems that companies like Amazon, Google and Microsoft previously used — and some continue to use — to assess applicants. To keep the questions up-to-date, the test prep service said, it regularly surveys members applying for tech positions.
  3. ↑ Ansari, Tasmia (2022-11-17). "The Ultimate Guide to Cracking Data Science Interviews". Analytics India Magazine. Retrieved 2023-06-10.
  4. ↑ Kolakowski, Nick (2022-12-08). "Which Programming Languages Are Growing?". Dice Insights. Retrieved 2023-06-10.
  5. 1 2 3 Sonmez, John; Butow, Eric (2019-09-11). Programming Interviews For Dummies. John Wiley & Sons. ISBN 978-1-119-56506-2. LeetCode is also a popular site for programmers who want to get up to speed.
  6. ↑ Harper, Jocelyn (2023), "Interview Insight: How to Get the Job", in Harper, Jocelyn (ed.), A Software Engineer's Guide to Seniority: A Guide to Technical Leadership, Berkeley, CA: Apress, pp. 19–28, doi:10.1007/978-1-4842-8783-5_4, ISBN 978-1-4842-8783-5, retrieved 2023-08-11, LeetCode is a platform that specializes in algorithm questions ranked from "Easy" to "Hard" based on the complexity of the subject and solution. They also have a forum where people share what interview questions they encountered in phone screens and on-site interviews to share with the larger public and to help software engineers prepare. I have been fortunate that the only time that I encountered a LeetCode problem during a screening process was for Amazon. ... On this last interviewing journey, I found myself enjoying practicing algorithm coding questions because I found alternative resources to LeetCode.
  7. ↑ leetcode.com Traffic analytics, ranking & audience (May 2025) Similarweb
  8. ↑ "Secretary of State". bizfileonline.sos.ca.gov. Retrieved 2024-03-21.
  9. 1 2 Curry, Rachel (2024-06-24). "AI is shaping the fate of software engineers, but there is a new way to succeed". CNBC. Retrieved 2024-06-26.
  10. ↑ Tang, Winston. "AI cannot replace software engineers—take it from someone who fought to become one and now helps others pursue the career". Fortune. Retrieved 2024-07-31.
  11. 1 2 Shumin, Liao. "IT Job Interview Prepper LeetCode Pockets USD10 Million From Lightspeed China". www.yicaiglobal.com. Retrieved 2023-08-16.
  12. ↑ Xing, Jessica. "Here's what job seekers need to know about LeetCode, the coding-skills platform millions of developers use to ace the notoriously difficult technical interviews at firms such as Apple, Amazon, and Google". Business Insider. Retrieved 2023-06-21.
  13. 1 2 "LeetCode - The World's Leading Online Programming Learning Platform". leetcode.com. Retrieved 2023-10-10.
  14. ↑ "Contest". LeetCode. Retrieved 2023-10-10.
  15. ↑ "What is Daily LeetCoding Challenge?". leetcode.com. Retrieved 2023-12-09.
  16. ↑ Nguyen, Nhan; Nadi, Sarah (2022-10-17). "An empirical evaluation of GitHub copilot's code suggestions". Proceedings of the 19th International Conference on Mining Software Repositories. MSR '22. New York, NY, USA: Association for Computing Machinery. pp. 1–5. doi:10.1145/3524842.3528470. ISBN 978-1-4503-9303-4. LeetCode questions come with test cases in various programming languages, ... (Python, Java, JavaScript, and C)
  17. ↑ 编程刷题平台 LeetCode 力扣所有题目均已支持华为仓颉语言 [All problems on the programming practice platform LeetCode are now supported in Huawei's Cangjie language]. Sohu. Retrieved 2024-12-03.
  18. ↑ "NeetCode.io". neetcode.io. Retrieved 2023-10-10.