Front End Developer Interview Questions In 2021

4 min readApr 25, 2021

Common skillset for a front end developer




Responsive design

Version control/Git


Frequently Asked Front End Interview Questions

Here in this article, we’ll be posting regularly inquired Front conclusion Meet Questions and Answers with the conviction that they will be accommodating for you to pick up higher marks. Moreover, to let you know that this article has been composed beneath the direction of industry experts and secured all the current competencies.

  1. What are the technical skills that are needed to be a front-end developer?

Technical frontend developer skills

  • HTML and HTML5
  • JavaScript and JQuery
  • Responsive Design
  • Testing
  • Creativity
  • Version Control Systems and other developer tools
  • CSS3

Apart from the above-mentioned technical skills, a good front end developer should also have the below-mentioned skills:-

  • Experience in any of the Content Management Systems (CMS) like WordPress, Drupal, and Joomla.
  • Cross-browser testing.
  • Knowledge about OOPS and PHP.
  • Basic knowledge about on-page SEO, and off-page SEO

2. What is HTML, XML


HTML stands for HyperText Markup Language. HTML is the standard markup language for creating Web pages. HTML describes the structure of a Web page. HTML consists of a series of elements. HTML elements tell the browser how to display the content.


  • XML stands for eXtensible Markup Language
  • XML is a markup language much like HTML
  • XML was designed to store and transport data
  • XML was designed to be self-descriptive


XHTML stands for EXtensible HyperText Markup Language. XHTML is a stricter, more XML-based version of HTML. XHTML is HTML defined as an XML application. XHTML is supported by all major browsers.

3. What is Lazy Loading?

Lazy loading is the practice of delaying load or initialization of resources or objects until they’re actually needed to improve performance and save system resources. … The benefits of lazy loading include: Reduces initial load time — Lazy loading a webpage reduces page weight, allowing for a quicker page load time.

4. What JavaScript templating libraries do you use and why?

I am listing down the most used JavaScript libraries for interview question preparation: Front-end.









5. What Is AJAX? What are the advantages of using it?

AJAX = Asynchronous JavaScript and XML. AJAX is a technique for creating fast and dynamic web pages. AJAX allows web pages to be updated asynchronously by exchanging small amounts of data with the server behind the scenes.

Pros of AJAX

  • Improved user experience
  • Reduced server hits and network load
  • Multi-browser support
  • Asynchronous processing
  • Faster page renders and improved response times
  • Platform and architecture neutrality

6. What is the difference between Responsive design and Adaptive design?

A website’s appearance changes depending on the browser’s viewport in responsive design. The width of the window is typically used by developers to evaluate the size of dynamically evolving items on the page.

An adaptive website, like a responsive website, can change the layout of the page based on the width of the browser, but in a different way.

Adaptive designs are made up of several versions of the same design, one for each size specified by the designer or user interface developer.

7. What is a class?

Let’s unveil any magic and see what a class really is. That’ll help in understanding many complex aspects.

In JavaScript, a class is a kind of function.

Here, take a look:

-class User {

-constructor(name) { = name; }

-sayHi() { alert(; }


-// proof: User is a function

  • alert(typeof User); // function

8. What is the difference between GET and POST?

A GET request is commonly used for AJAX API calls, while a POST request is usually used to store data in a database or send data through a form.

POST requests are used in two stages and are not visible to the user. GET requests are limited to secure and can be seen by the user in the URL. POST requests are therefore more reliable.

9. What is a CSS float and why you should use it?

This technical question is ideally fit for more junior front-end developers and assesses their CSS knowledge. Although technological knowledge is relevant, it is the “why” that matters most in this case. The explanation for the candidate’s use of floats will help you figure out their approach to website styling — and whether or not they’re a good match for your business.

10. What is Cross-browser testing?

Cross Browser Testing is a method of testing that determines whether an application performs as planned across multiple browsers and degrades gracefully. It is the method of determining whether or not your application is compatible with various browsers.

11. What are the building blocks of HTML?

Attribute: An attribute in HTML provides additional information about an element, and it is used in Start TAG. There are two fields in it: Name and Value.

Tags: Tags in HTML are written between the and > brackets and surround and add context to the text.

Elements HTML elements are described as anything written inside tags in an HTML file.

12. What are the benefits of using Anime.JS?

  • Layered CSS transforms
  • Controls and callbacks
  • Animate anything
  • Effects and Animations
  • Scenes and Cameras
  • Data loaders and Shaders


As a result, these are the most relevant interview questions and answers for front-end developers. It will help you in your just-in-time planning for the front-end creation work interview. Please let me know if there are any other relevant front-end developer questions that I missed in the comments.