# LeetCode
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> Source: https://en.wikipedia.org/wiki/LeetCode
> Source revision: 1352410305
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)
{{short description|Online platform for coding interview preparation}}
{{Infobox website
| name =
| logo = 250px
| type = [Private](/source/Privately_held_company)
| industry = Software
|owner = Leetcode LLC
| founded = 7 August 2015
| founder = Winston Tang
| location_city = [Palo Alto](/source/Palo_Alto), [California](/source/California)
| location_country = [US](/source/United_States)
| key_people = Hercy Chang (CEO)
| num_employees = 264 (2025)[[https://leadiq.com/c/leetcode/5a6861465700003b015b2278/employee-directory LeetCode Employee Directory, Headcount & Staff] ''LeadIQ'']
|revenue = US$8 million[[https://siliconvalleyjournals.com/company/leetcode LeetCode: Contact Details, Revenue, Funding, Employees and Company Profile]
''Silicon Valley Journal''] (2024)
| website = * {{official website|2=leetcode.com}}
* {{official website||2=leetcode.cn}} (in Chinese)
}}
'''LeetCode''' is an [online platform](/source/online_discussion_platform) for [software coding interview](/source/Coding_interview) preparation. The platform provides coding and algorithmic problems intended for users to practice [coding](/source/Software_development).[ Since the company founding in 2015, the LeetCode platform has gained popularity among job seekers in the [software industry](/source/software_industry) and coding enthusiasts as a resource for technical interviews and coding competitions.][{{Cite news |last=Singer |first=Natasha |date=2023-04-05 |title=For Lower-Income Students, Big Tech Internships Can Be Hard to Get |url=https://www.nytimes.com/2023/04/05/business/tech-internship-application-grind.html |access-date=2023-08-09 |work=The New York Times |language=en |quote=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.}}][{{Cite web |last=Ansari |first=Tasmia |date=2022-11-17 |title=The Ultimate Guide to Cracking Data Science Interviews |url=https://analyticsindiamag.com/the-ultimate-guide-to-cracking-data-science-interviews/ |access-date=2023-06-10 |website=Analytics India Magazine |language=en-US}}][{{Cite web |last=Kolakowski |first=Nick |date=2022-12-08 |title=Which Programming Languages Are Growing? |url=https://www.dice.com/career-advice/which-programming-languages-are-growing |access-date=2023-06-10 |website=Dice Insights |language=en}}][{{Cite book |last=Sonmez |first=John |url=https://books.google.com/books?id=rEOvDwAAQBAJ&dq=LeetCode&pg=PA108 |title=Programming Interviews For Dummies |last2=Butow |first2=Eric |date=2019-09-11 |publisher=John Wiley & Sons |isbn=978-1-119-56506-2 |language=en |quote=LeetCode is also a popular site for programmers who want to get up to speed.}}][{{Citation |last=Harper |first=Jocelyn |title=Interview Insight: How to Get the Job |date=2023 |work=A Software Engineer's Guide to Seniority: A Guide to Technical Leadership |pages=19–28 |editor-last=Harper |editor-first=Jocelyn |url=https://doi.org/10.1007/978-1-4842-8783-5_4 |access-date=2023-08-11 |place=Berkeley, CA |publisher=Apress |language=en |doi=10.1007/978-1-4842-8783-5_4 |isbn=978-1-4842-8783-5 |quote=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.|url-access=subscription }}] As of 2025, the website has 26.3 million monthly visitors.[[https://www.similarweb.com/website/leetcode.com leetcode.com Traffic analytics, ranking & audience (May 2025)] ''[Similarweb](/source/Similarweb)'']
== History ==
LeetCode was founded in Silicon Valley in 2015 by Winston Tang.[{{Cite web |title=Secretary of State |url=https://bizfileonline.sos.ca.gov/search/business |access-date=2024-03-21 |website=bizfileonline.sos.ca.gov}}][{{Cite web |last=Curry |first=Rachel |date=2024-06-24 |title=AI is shaping the fate of software engineers, but there is a new way to succeed |url=https://www.cnbc.com/2024/06/24/ai-shaping-fate-of-software-engineers-but-there-is-new-way-to-succeed.html |access-date=2024-06-26 |website=CNBC |language=en}}] After moving to the US from Malaysia in 2005, Tang founded the company, citing his own experiences working at Amazon and Google as inspiration.[{{Cite web |last=Tang |first=Winston |title=AI cannot replace software engineers—take it from someone who fought to become one and now helps others pursue the career |url=https://fortune.com/2024/07/30/ai-cannot-replace-software-engineers-or-threaten-their-careers/ |access-date=2024-07-31 |website=Fortune |language=en}}]
LeetCode expanded its operations to China in 2018, providing Chinese problems, solutions and forums on its Chinese website ''Likou'' ({{Zh|c=力扣|p=Lìkòu}}).[{{Cite web |last=Shumin |first=Liao |title=IT Job Interview Prepper LeetCode Pockets USD10 Million From Lightspeed China |url=https://www.yicaiglobal.com/news/it-job-interview-prepper-leetcode-pockets-usd10-million-from-lightspeed-china |access-date=2023-08-16 |website=www.yicaiglobal.com |language=en}}] In 2021, LeetCode secured its first round of funding, receiving a $10 million investment from [Lightspeed China Partners](/source/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](/source/Time_complexity) and [memory usage](/source/Memory_management), and is ranked against other submissions in the LeetCode database.][{{Cite web |last=Xing |first=Jessica |title=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 |url=https://www.businessinsider.com/leetcode-coding-test-apple-amazon-google-technical-interview-prep-job-2021-11 |access-date=2023-06-21 |website=Business Insider |language=en-US}}]
Additionally, LeetCode provides its users with mock interviews and online assessments. LeetCode hosts weekly and biweekly contests, each having 4 problems.[{{Cite web |title=LeetCode - The World's Leading Online Programming Learning Platform |url=https://leetcode.com/ |access-date=2023-10-10 |website=leetcode.com}}] After participating in a contest for the first time, one gets assigned a ranking, which can be found in their profile.[{{Cite web |title=Contest |url=https://leetcode.com/contest/ |access-date=2023-10-10 |website=LeetCode |language=en}}] 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.[{{Cite web |title=What is Daily LeetCoding Challenge?|url=https://leetcode.com/discuss/general-discussion/655704/ |access-date=2023-12-09 |website=leetcode.com}}]
LeetCode supports a wide range of programming languages, including [Java](/source/Java_(programming_language)), [Python](/source/Python_(programming_language)), [JavaScript](/source/JavaScript), and [C](/source/C_(programming_language)).[{{Cite book |last=Nguyen |first=Nhan |title=Proceedings of the 19th International Conference on Mining Software Repositories |last2=Nadi |first2=Sarah |date=2022-10-17 |publisher=Association for Computing Machinery |isbn=978-1-4503-9303-4 |series=MSR '22 |location=New York, NY, USA |pages=1–5 |chapter=An empirical evaluation of GitHub copilot's code suggestions |doi=10.1145/3524842.3528470 |quote=LeetCode questions come with test cases in various programming languages, ... (Python, Java, JavaScript, and C) |doi-access=free}}] Since September 2024, LeetCode China supports [Huawei](/source/Huawei)'s [Cangjie programming language](/source/Cangjie_programming_language) for all problems.[{{Cite web |title= |script-title=zh:编程刷题平台 LeetCode 力扣所有题目均已支持华为仓颉语言 |trans-title=All problems on the programming practice platform LeetCode are now supported in Huawei's Cangjie language |url=https://www.sohu.com/a/809062659_114760 |access-date=2024-12-03 |website=[Sohu](/source/Sohu)}}]
The platform features forums where users can engage in discussions related to problems, the interview process, and share their interview experiences.[{{Cite web |title=NeetCode.io |url=https://neetcode.io/roadmap |access-date=2023-10-10 |website=neetcode.io}}]{{Better source needed|date=October 2023}} 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.