BFE.dev
Solve front-end JavaScript, TypeScript and React interview problems
BFE.dev calls itself LeetCode for front-end. You solve JavaScript coding problems, TypeScript type puzzles, React tasks, CSS questions and quizzes on how JavaScript really behaves. There are also front-end system design and general interview questions. The site lists more than 600 questions in total.
Freemium · Browser · Intermediate
About BFE.dev
It trains the kind of code front-end interviews ask for, such as writing debounce, a promise helper or a deep clone by hand. It suits developers preparing for front-end interviews and anyone who wants to know JavaScript well.
You code in a VS Code style editor in the browser and run your code right away. Community solutions are free. Some content, such as company lists, is marked as premium.
On Breakpoint since 23 Oct 2026.