A list of helpful front-end related questions you can use to interview potential candidates, test yourself or completely ignore.

View the Project on GitHub h5bp/Front-end-Developer-Interview-Questions

Front-end Job Interview Questions

This file contains a number of front-end interview questions that can be used when vetting potential candidates. It is by no means recommended to use every single question here on the same candidate (that would take hours). Choosing a few items from this list should help you vet the intended skills you require.

Note: Keep in mind that many of these questions are open-ended and could lead to interesting discussions that tell you more about the person's capabilities than a straight answer would.

Table of Contents

  1. General Questions
  2. HTML Questions
  3. CSS Questions
  4. JS Questions
  5. Network Questions
  6. Coding Questions
  7. Fun Questions

Getting Involved

  1. Contributors
  2. How to Contribute
  3. License

General Questions:

HTML Questions:

CSS Questions:

JS Questions:

duplicate([1,2,3,4,5]); // [1,2,3,4,5,1,2,3,4,5]

Testing Questions:

Performance Questions:

Network Questions:

Coding Questions:

Question: What is the value of foo?

var foo = 10 + '20';

Question: How would you make this work?

add(2, 5); // 7
add(2)(5); // 7

Question: What value is returned from the following statement?

"i'm a lasagna hog".split("").reverse().join("");

Question: What is the value of

( || ( = "bar" ) );

Question: What is the outcome of the two alerts below?

var foo = "Hello";
(function() {
  var bar = " World";
  alert(foo + bar);
alert(foo + bar);

Question: What is the value of foo.length?

var foo = [];

Question: What is the value of foo.x?

var foo = {n: 1};
var bar = foo;
foo.x = foo = {n: 2};

Fun Questions:


This document started in 2009 as a collaboration of @paul_irish @bentruyman @cowboy @ajpiano @SlexAxton @boazsender @miketaylr @vladikoff @gf3 @jon_neal @sambreed and @iansym.

It has since received contributions from over 100 developers.