Top 25+ Frontend Interview Questions and Answers

Frontend Interview Questions – Are you preparing for your frontend interview and wondering what questions might come your way?

You’re not alone!

These interviews cover a wide range of topics, from basic HTML and CSS to more complex JavaScript frameworks like React and Angular. 

There’s a lot to get ready for, but don’t stress! 

In this article, we’ve compiled a complete list of the top 25+ frontend interview questions with simple answers to help you grasp the concepts easily. 

This guide will give you the knowledge and confidence to excel in your next frontend interview.

Let’s begin and get you interview-ready!

Front-End Development Jobs in India

Frontend development is creating the visual and interactive parts of a website that users see and interact with directly. It involves using languages like HTML, CSS, and JavaScript to design and structure web pages. 

In India, there’s a growing demand for frontend developers due to the expanding IT sector and the increasing reliance on digital platforms. 

Research shows that the need for front-end developers is predicted to increase by 25% over the next decade in India. This growth rate is much faster compared to the average for all types of jobs.

Companies across various industries, including IT services, e-commerce, and FinTech, are actively hiring frontend talent to improve their online presence and user experiences.

Among these industry leaders are:

• Infosys
• Tata Consultancy Services (TCS)
• Wipro
• Accenture
• IBM India

To secure a position at one of these industry giants, you need to do two things,

Step 1: Search and apply

Start by actively seeking out open positions for frontend developers and submit your job applications. You can use reputable IT job portals like Hirist to find open job positions specifically tailored to front end development roles.

Step 2: Prepare for the interview

Once you’ve applied, start with front end developer interview preparation. This involves familiarizing yourself with common front end interview questions and answers and brushing up on your technical skills.  

By following these steps, you can increase your chances of landing your desired frontend role at a top-tier company in India.

Front End Developer Interview Questions and Answers for Freshers

Here are some commonly asked front end developer interview questions for freshers: 

1. What is the difference between HTML and HTML5?

This is one of the most common front end dev questions you might encounter as a fresher. Here’s how you should answer it.

HTML is the basic language used to create web pages, while HTML5 is a newer version with extra features like new tags for sections of a page and built-in support for playing audio and video.

2. Explain the box model in CSS.

The CSS box model describes how elements are displayed on a webpage. It consists of content, padding, border, and margin. Each of these components contributes to the total space occupied by the element.

3. What is the purpose of JavaScript?

JavaScript is a programming language used to create dynamic and interactive elements on web pages. It enables functionality like form validation, DOM manipulation, and asynchronous requests, enhancing the user experience.

4. What is responsive web design?

This is another common front end questions you may come across in interviews. 

Responsive web design means making websites that look good and work well on different devices, like computers, tablets, and phones. It’s important because people use lots of different devices to browse the internet, so we want our websites to look good no matter what. 

5. How do you optimize website performance?

Website performance can be optimized by techniques such as

• Minification of CSS and JavaScript files
• Browser caching
• Optimizing images
• Reducing HTTP requests
• Using Content Delivery Networks (CDNs) 

Junior Front End Developer Interview Questions and Answers

Here are some common front end web developer interview questions and answers: 

6. What are some best practices for writing clean and maintainable HTML and CSS code?

This is one of the most popular frontend developer interview questions for junior developers. This is how you should answer it.

It’s important to use proper indentation and comments to keep the code organized. Also, using meaningful class and ID names helps others understand the purpose of each element. Avoiding inline styles and keeping CSS separate from HTML improves code maintainability.

7. Explain the concept of progressive web apps (PWAs).

Progressive web apps (PWAs) are advanced web applications that utilize modern web technologies to offer users an experience similar to native apps. They have the capability to function offline, deliver push notifications, and can even be installed directly onto a user’s device’s home screen.

8. What is the purpose of JavaScript frameworks like React and Angular?

JavaScript frameworks like React and Angular simplify the process of building complex web applications by providing reusable components, efficient state management, and seamless data binding. They help developers create interactive user interfaces more efficiently and maintainably.

Also Read - Top 25+ HTML CSS JavaScript Interview Questions and Answers

9. How do you handle cross-browser compatibility issues in frontend development?

Cross-browser compatibility issues arise when a website looks or behaves differently across different web browsers. To address this, we can use feature detection libraries like Modernizr, prefix CSS properties with vendor prefixes, and test our code on multiple browsers during development.

10. Explain the difference between synchronous and asynchronous JavaScript.

Synchronous JavaScript executes one task at a time, blocking further execution until the current task is completed. Asynchronous JavaScript allows multiple tasks to be executed concurrently, without waiting for each task to finish before proceeding. 

This is commonly used for tasks like fetching data from a server or handling user input without freezing the UI.

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Front End Developer Interview Questions for Experienced

Here are some important interview questions for a front end developer with experience: 

11. Can you explain the differences between CSS Grid and Flexbox layout models, and when would you use each one?

CSS Grid is best suited for two-dimensional layouts, allowing for precise control over rows and columns. Flexbox, on the other hand, is ideal for one-dimensional layouts, providing flexibility in arranging items along a single axis. CSS Grid is often used for overall page layout, while Flexbox is great for arranging items within a layout.

12. What are some techniques for optimizing frontend code for search engine optimization (SEO)?

To optimize frontend code for SEO, 

• Ensure proper semantic markup in HTML.
• Use descriptive title tags and meta descriptions containing relevant keywords.
• Incorporate structured data markup such as Schema.org.
• Optimize images for fast loading times.
• Reduce unnecessary code to improve page loading speed.

13. What is the purpose of version control systems like Git?

Version control systems like Git serve the purpose of tracking changes made to files and enabling collaboration among developers. They facilitate code versioning, branching, and merging and provide a convenient way to revert back to previous states if needed.

14. Can you discuss the role of performance monitoring and optimization in ongoing frontend development projects?

Performance monitoring involves regularly assessing key performance metrics such as page load times, time to interact, and resource utilization. 

By using tools like Google PageSpeed Insights, Lighthouse, or New Relic, developers can identify performance bottlenecks and implement optimizations to improve user experience and conversion rates. Ongoing performance optimization ensures that web applications remain fast, efficient, and responsive over time.

15. Describe how you would reverse a singly linked list in JavaScript. Provide a code implementation.

This is one of the few DSA questions for front end developer you might be asked. Here’s how you should answer it.

To reverse a singly linked list, we can iterate through the list and change the direction of pointers. Here’s an example:

class ListNode {

    constructor(val) {

        this.val = val;

        this.next = null;

    }

}

function reverseLinkedList(head) {

    let prev = null;

    let current = head;

    while (current !== null) {

        let nextTemp = current.next;

        current.next = prev;

        prev = current;

        current = nextTemp;

    }

    return prev;

}

// Usage:

let head = new ListNode(1);

head.next = new ListNode(2);

head.next.next = new ListNode(3);

head.next.next.next = new ListNode(4);

let reversedHead = reverseLinkedList(head);

// Output: 4 -> 3 -> 2 -> 1

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Senior Front End Developer Interview Questions

Here are some of the most important interview questions for senior front end developer: 

16. What is the purpose of a task runner like Gulp or Grunt?

Task runners like Gulp or Grunt serve to automate recurring tasks in front-end development, such as compressing, combining, and enhancing CSS and JavaScript files. By Automating these processes, they boost efficiency and uphold code standards.

17. Can you explain the concept of lazy loading in web development and how it improves performance?

Lazy loading defers non-essential resource loading until necessary, reducing initial page load times and data transfer. It’s implemented with JavaScript to load resources dynamically, triggered by user actions like scrolling or clicking.

18. Describe your experience in implementing and optimizing web accessibility standards in frontend development projects.

“I prioritize adhering to web accessibility guidelines like WCAG, using semantic HTML, ARIA attributes, and focus management. Regular audits and user testing ensure inclusivity and identify accessibility barriers for mitigation.”

19. How do you approach architectural decisions in frontend development, particularly when scaling and maintaining large codebases?

This is one of the most important front end developer technical interview questions. This is how you should answer it.

“I focus on modularity and scalability by breaking down applications into reusable components, utilizing design patterns like MVC, and implementing state management solutions. Code reviews and documentation maintain consistency and collaboration.”

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Front End Developer Coding Interview Questions

Here are the most commonly asked front end coding questions with answers:

20. Create a CSS animation that animates the color of a button from red to blue when hovered over.

You might come across front end engineer interview questions like this one. Here’s how you should answer it. 

.button {

    background-color: red;

    transition: background-color 0.5s;

}

.button:hover {

    background-color: blue;

}

21. Write a function to toggle the visibility of an HTML element with a specific ID when a button is clicked.

function toggleVisibility() {

    const element = document.getElementById(‘targetElement’);

    element.style.display = (element.style.display === ‘none’) ? ‘block’ : ‘none’;

}

22. Write a function to validate an email input field in a form. It should check if the input is a valid email address and display an error message if not.

function validateEmail() {

    const email = document.getElementById(’emailInput’).value;

    const pattern = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;

    const isValid = pattern.test(email);

    if (!isValid) {

document.getElementById(‘error’).innerText = ‘Invalid email address’;

    } else {

document.getElementById(‘error’).innerText = ”;

    }

}

Platform and Company-Specific Frontend Interview Questions

Here are some important platform and company-specific front end developer interview questions and answers:

23. How does React native works internally? 

According to Glassdoor, this is one of the most common IBM front end developer interview questions.

React Native works by rendering native UI components using JavaScript. It bridges the gap between JavaScript and native platform APIs, allowing developers to write code once and deploy it across multiple platforms, resulting in efficient cross-platform mobile app development.

Also Read - Top 20 React Native Interview Questions With Expert Answers

24. What is Prototypal Inheritance? How does it work?

This is a common Microsoft front end interview question.

Prototypal inheritance is a JavaScript feature where objects inherit properties and methods directly from other objects. Each object has a prototype object, and when a property or method is accessed, JavaScript looks up the prototype chain until it finds the property or method.

25. What is a JavaScript closure?

This is one of the most common Amazon front end developer interview questions.

A JavaScript closure is a function that retains access to its lexical scope, even after the scope has closed. It allows functions to access and manipulate variables from their outer scope, preserving state and creating private variables.

26. How would you utilize Google’s Material Design principles and guidelines to design a user-friendly and visually appealing interface for a web application?

This is how you should answer Google front end interview questions.

“I’d follow Google’s design rules to keep things consistent and friendly. By using elements like cards and buttons as suggested, I’d aim to make the site user-friendly and visually appealing.”

27. What is the technology stack used by Magento?

Here’s how you should answer such Magento 2 frontend developer interview questions.

Magento relies on MySQL or MariaDB for databases and PHP for programming. It utilizes PHP 7.0.2 to 7.0.10, with the exception of PHP 7.0.5 due to an issue with the Magento code compiler. Additionally, it incorporates Zend Framework components in its technology stack.

28. How do you use Magento’s LESS/CSS preprocessing to customize the appearance of storefront elements?”

This is one of the most common Magento front end developer interview questions. 

“I use Magento’s LESS/CSS preprocessing to easily customize colours, fonts, and styles across the storefront by modifying variables and overriding default stylesheets.”

29. Can you describe a situation where you were tasked with implementing a complex Drupal front-end design?

This is one of the most popular Drupal front end developer interview questions. 

“I was tasked with implementing a complex Drupal front-end design involving intricate layout structures and dynamic content. By using Drupal’s theming system and customizing templates, I successfully translated the design into a functional and visually appealing website.”

30. How would you handle cookies and cache in a PHP application?

As per AmbitionBox, you may come across such Flipkart front end developer interview questions.

“In a PHP application, I manage cookies by setting them using the setcookie() function with parameters like name, value, expiration time, and path. 

For cache handling, I use PHP’s caching mechanisms such as APCu, Memcached, or OPcache to store and retrieve data efficiently, enhancing application performance and reducing database queries.”

31. How would you integrate Infosys’s proprietary tools or frameworks, such as Infosys Nia or EdgeVerve, into front-end development projects to enhance functionality and meet client requirements?

You can expect similar Infosys front end developer interview questions.

“To integrate Infosys’s proprietary tools like Infosys Nia or EdgeVerve into front-end projects, I’d first analyze project requirements and tool capabilities. 

Then, I’d collaborate with relevant teams to implement APIs or SDKs provided by these tools, leveraging their functionalities to enhance project features and meet client expectations effectively.”

32. What is event bubbling?

This is one of the common Nagarro interview questions for front end developer.

Event bubbling is a phenomenon in JavaScript where an event triggered on a nested element will propagate upwards through its parent elements, triggering their respective event handlers.

33. What is pseudo classes and element?

NeoSOFT interview questions for front end developer may include this one. 

Pseudo-classes and elements in CSS allow styling based on certain states or properties that can’t be represented by simple selectors, like :hover, :first-child, ::before, and ::after.

34. How would you use Oracle JET (JavaScript Extension Toolkit) to develop responsive and enterprise-grade web applications?

This is one of the most popular Oracle front end developer interview questions.

“I’d harness Oracle JET’s modular architecture and pre-built components to craft responsive web applications. Using its features, like templating, data visualization, and accessibility, ensures enterprise-grade functionality and user experience.”

35. How do you integrate Salesforce Lightning Web Components (LWC) to enhance user interface functionality?

This is among the most popular Salesforce front end developer interview questions.

“I integrate Salesforce Lightning Web Components to improve user interface functionality by using their modular structure and built-in features, ensuring an improved user experience within Salesforce applications.”

36. How would you optimize WordPress themes for performance and usability?

You might encounter WordPress front end developer interview questions like this one. 

“To optimize WordPress themes, I focus on minimizing HTTP requests, optimizing images, using caching plugins, and implementing lazy loading. I also prioritize clean code, minimize plugins, and leverage browser caching for improved performance and usability.”

Also Read - Top 25 AngularJS Interview Questions and Answers

Front End Developer MCQ Questions

Here are some important frontend MCQ questions: 

37. Which of the following is NOT a valid CSS selector?

a) #header

b) .container

c) <div>

d) p:first-child

Answer: c) <div>

Explanation: <div> is an HTML element, not a CSS selector.

38. What does HTML stand for?

a) Hyper Text Markup Language

b) Hyperlinks and Text Markup Language

c) Home Tool Markup Language

d) Hyperlinks and Text Modification Language

Answer: a) Hyper Text Markup Language

Explanation: HTML stands for Hyper Text Markup Language.

39. Which JavaScript method is used to add new items to the end of an array?

a) push()

b) pop()

c) concat()

d) splice()

Answer: a) push()

Explanation: The push() method adds new items to the end of an array.

40. What does the “display: none;” CSS property do?

a) It hides the element but keeps the space it occupies.

b) It hides the element and removes the space it occupies.

c) It displays the element as a block-level element.

d) It displays the element as an inline element.

Answer: b) It hides the element and removes the space it occupies.

Explanation: The “display: none;” property hides the element and removes the space it occupies from the document flow.

Conclusion

There you go! Now, you can easily prepare for your interview with these 25+ most commonly asked frontend interview questions and answers. And if you are still searching for a job, visit Hirist. Here, you can easily find front end jobs in the best IT companies in India. We hope you have a good front end interview experience.