LeetCode

What LeetCode is

LeetCode is a website and online coding platform at leetcode.com for practicing programming problems, preparing for technical interviews, joining contests, and running code in a browser. LeetCode also has official mobile listings on the App Store and Google Play, with its own app page describing quick practice, collections, events, and progress tracking.

Problem library and online judge

The core experience is a problem page: a prompt, examples, constraints, an editor, supported languages, test cases, submissions, and feedback from an online judge. Users write a solution, run it, submit it, and see whether it passes hidden tests within time and memory limits. That loop makes LeetCode feel more like a practice lab than a normal tutorial site.

Interview preparation

LeetCode is especially associated with software engineering interview practice. Its questions often focus on arrays, strings, linked lists, trees, graphs, dynamic programming, databases, concurrency, and system-design-adjacent reasoning. Practicing on the site can help people recognize patterns, but strong interview preparation also needs explanation, communication, debugging, and judgment about tradeoffs.

Study plans and explore pages

The Explore area and study-plan style pages organize practice into guided tracks. This helps users avoid staring at a giant problem list with no route through it. A beginner may start with arrays or SQL, while a more experienced user may focus on dynamic programming, graph traversal, or company-tagged interview themes.

Contests and ranking

LeetCode contests turn practice into timed problem solving. Participants solve several problems during a scheduled event, then receive ranking and performance feedback. Contests reward speed, pattern recognition, and implementation accuracy, but they are not a complete measure of software engineering ability.

Community and explanations

LeetCode's Discuss pages, editorial explanations, solution posts, and comments are part of the learning environment. They let users compare approaches, learn common patterns, and see why a brute-force idea fails or why a data structure makes a solution faster. The quality varies, so good learners cross-check explanations rather than copying a clever answer without understanding it.

Business and assessment uses

LeetCode also presents services for companies, including online assessments and business opportunities tied to identifying technical talent. That gives the platform two audiences: individuals practicing for interviews and organizations using coding tasks as part of hiring, training, or event workflows.

Why it matters

LeetCode matters because it shaped how many programmers prepare for coding interviews. It made algorithm practice easy to repeat, compare, discuss, and measure, while also creating a culture where interview prep can become its own skill. Used well, it builds fluency with patterns and edge cases. Used narrowly, it can overemphasize puzzle speed at the expense of maintainable software design.

WHOIS domain data

Data pulled: June 1, 2026 · View current WHOIS record

Domain

leetcode.com

IP address

172.66.154.160

Registrar

GoDaddy.com, LLC

WHOIS server

whois.godaddy.com

Referral URL

http://www.godaddy.com

Created

July 11, 2010

Updated

March 25, 2025

Expires

July 11, 2034

Nameservers

melinda.ns.cloudflare.com (173.245.58.198); rob.ns.cloudflare.com (108.162.193.140)

Domain status

clientDeleteProhibited; clientRenewProhibited; clientTransferProhibited; clientUpdateProhibited