LeetCode

LeetCode LLC, doing business as LeetCode, is an online platform for coding interview preparation. The platform provides coding and algorithmic problems intended for users to practice coding.^[1] LeetCode has gained popularity among job seekers in the software industry and coding enthusiasts as a resource for technical interviews and coding competitions.^{[1][2][3][4][5]}

LeetCode, LLC

Company type	Private
Industry	Software
Founded	August 7th, 2015
Founder	Winston Tang
Headquarters	Palo Alto, California , US
Key people	Hercy Chang (CEO)
Number of employees	26
Website	leetcode.com leetcode.cn

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.^[1] The performance of users' solutions is evaluated based on execution speed and memory usage, and is ranked against other submissions in the LeetCode database.^[6]

Additionally, LeetCode provides its users with mock interviews and online assessments. LeetCode hosts weekly and biweekly contests, each having 4 problems.^[4][7] After participating in a contest for the first time, one gets assigned a ranking, which can be found in their profile.^[8] 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.^[9]

LeetCode supports a wide range of programming languages, including Java, Python, JavaScript, and C.^[10] In September 2024, LeetCode China supports Huawei's Cangjie programming language [zh] for all problems.^[11]

The platform features forums where users can engage in discussions related to problems, the interview process, and share their interview experiences.^[4]

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.^{[12][better source needed]} As of April 2025, LeetCode offers 3525 questions across its three levels of difficulty; with 873 questions categorized as easy, 1829 as medium, and 823 as hard.^{[7][better source needed]}

History

LeetCode was founded in Silicon Valley in 2015 by Winston Tang.^[13][14] After moving to the US from Malaysia in 2005, Tang founded the company, citing his own experiences working at Amazon and Google as inspiration.^[15][14]

LeetCode expanded its operations to China in 2018, providing Chinese problems, solutions and forums in leetcode.cn (Chinese: 力扣; pinyin: Lìkòu).^[16] In 2021, LeetCode secured its first round of funding, receiving a $10 million investment from Lightspeed China Partners.^[16]

See also

• Competitive programming