Top 40+ Web Developer Interview Questions and Answers for 2025

Section-I. Top Web Developer Interview Questions for Freshers

If you’re a beginner looking to start your career in web development, you are expected to be aware of certain basics, not only pertaining to the concepts but also to the field as a whole. Here are some of the frequently-asked junior web developer interview questions. Knowing the answers to these will offer a good grasp of basics that you can leverage in interviews for web developer positions. 

1. What skills should a good Web Developer have?

Web development professionals should have the following key skills: 

• Proficiency in Hypertext Markup Language (HTML) and Cascading Style Sheets (CSS)
• In-depth knowledge of Python, Ruby, and PHP
• Familiarity with DSL (Domain Specific Language), such as SQL
• A strong sense of JavaScript and JavaScript libraries, including JQuery
• Problem-solving capabilities

2. Are you aware of the roles and responsibilities of a Web Developer?

The primary responsibilities of a web developer include:

• Testing and debugging web applications
• Designing, developing, and deploying web applications
• Uploading websites onto servers and registering them with multiple search engines
• Coordinating with other programmers and designers to ensure the smooth development of web projects
• Fixing bugs, troubleshooting, and resolving problems
• Implementing contingency plans in the case of system failures 
• Developing proper code structures for solving specific tasks
• Providing support in the maintenance and upkeep of websites

3. What are the added benefits of HTTP/2 compared to HTTP 1.1?

HTTP/2 has a number of notable advantages over HTTP 1.1, which are: 

• Advanced server-push technology
• Reduced network footprint
• Uses network resources more effectively
• Eliminates security issues related to HTTP 1.1, such as a response splitting attack
• Enables superior capabilities, including effective TLS handling, prioritization, multiplexing, compression, and flow control
• Compact command representation, which facilitates easier implementation and processing 
• Robust and efficient data processing between server and client 
• Improved throughput and lower network latency
• Less error-prone

4. Can you list a few ways to speed up Page Loading?

The following actions should be performed to improve page loading speed:

• Decrease image size
• Clear unwanted widgets
• HTTP compression
• Placing script reference in the bottom and CSS on the top 
• Reduce redirects
• Minimize lookups
• Caching

5. How is XHTML different from HTML?

XHTML differs from HTML in many ways, for example:

• All tags in XHTML must be in lowercase
• XHTML requires the use of double quotes for all attributes
• In XHTML, tags must be properly closed  
• XHTML does not permit an inline element to contain a block-level element 

6. Explain Webpack.

When given dependencies-containing modules, Webpack creates static assets to represent those modules.

JavaScript module bundler Webpack is free and open-source. Although it is designed primarily for JavaScript, it may also modify front-end assets like HTML, CSS, and pictures if the appropriate loaders are also present. Using modules with dependencies,

Implementing various Java script files without worrying about which would load first is beneficial. It results in shorter code. In addition to java script, it assists in turning many other files into modules. It assembles many Java script modules.

7. List out newly introduced input types, APIs, form elements, and elements that support media content in HTML5.

Input types, including Date, Date Time-local, time, week, month, email, tel, URL, search, range, color, and number, are among the new ones introduced by HTML5. to enhance user interaction and make forms more engaging. However, a browser will interpret these new input types like a standard text box if it is unable to recognize them.

8. State the difference between span tag and div tag in HTML5. 

Div Tag

The web page, a hypertext document created by a website and presented to a user via a web browser, uses HTML elements to format and provide semantics to various sections of the content. The general HTML components div> and span> are both used to identify two different sections of a website. These tags are used for both structuring and styling. Here, we've examined the distinctions between the HTML tags for div and span.

Span Tag

To stylize text, use the generic inline element span>. A part of the inline content is given style. The inline element merely takes up as much room as the text and does not require a new line. These tags can be used for brief passages of text, images, links, and other HTML components that may be displayed inline with other content.

9. Explain HTML5 Web storage.

Web Storage in HTML Web storage allows web applications to store data locally in the user's browser. Application data had to be preserved in cookies and sent with each server request before HTML5. Web storage, which is more secure, allows for the local storing of large amounts of data without impairing a website's operation.

10. Explain DOM (Document Object Model).

The DOM enables programmatic reading, manipulation, and modification of an XML document. The XMLReader class also reads XML, but it does so in a non-cached, forward-only, read-only manner.

11. What do you know about pair programming?

Pair software programming is a sequential model in which two programmers collaborate on the same computer. While the driver is writing code, the observer or navigator reviews each line of programming as it is entered. Positions for software developers frequently change.

12. While building a web application, how do you consider SEO, maintainability, UX, performance, and security?

The ability to balance and comprehend these disparate factors is essential for any web developer. In addition, their response will indicate which factors they will prioritize when coding. 

If you work for an online publication, performance and SEO will be more important. While the driver is writing code, the observer or navigator reviews each line of programming as it is entered. Positions for software developers frequently change.

13. State the difference between SVG (Scalable Vector Graphics) and Canvas.

SVG is an XML-based language for describing 2D graphics. Canvas generates 2D graphics in real-time (with JavaScript). Because SVG is based on XML, every element is accessible through the SVG DOM. JavaScript event handlers can be attached to an element. 

12. What is Type Coercion in JavaScript?

The automatic or implicit conversion of values between different data types is known as type coercion (such as strings to numbers).

Both explicit and implicit type coercion is possible. Explicit type coercion occurs when developers explicitly state their goal to convert between types by writing the necessary code, such as Number(value) (or type casting).

13. State the difference between <window.onload> and <onDocumentReady>?

The window.onload method is called after the entire web page has been loaded. This includes all memory-based and model elements such as the head tag, headline, and all other tags such as template files, images, and videos. The onload method is called by passing it a function. After the object has been loaded, the called function would be executed.

14. Describe the different kinds of HTTP requests supported by RESTful Web services. 

The most common HTTP request methods are as follows:

POST, GET, PUT, PATCH, and DELETE are the five main or most often used HTTP verbs (or methods, as they are officially known). These stand for the CRUD (create, read, update, delete) operations, in that order. Other verbs exist as well, albeit they are used less frequently.

Section-II. Web Developer Interview Questions for Experienced Web Developers 

If you’ve had some experience as a web developer and are interviewing for senior web developer positions, then you are likely to come across some of these frequently-asked senior web developer interview questions. 

15. How does CORS work?

An HTML5-supported mechanism, Cross-Origin Resource Sharing, or CORS, enables the requesting of resources on web pages from other domains outside the domains from where the resources originated. 

16. What is an Entity Tag?

An Entity Tag, or ETag, is an integral element of HTTP (Hypertext Transfer Protocol): the protocol that facilitates communication between servers and web browsers. Entity Tag is one of the many mechanisms that the Hypertext Transfer Protocol provides for cache validation, allowing conditional requests from a client.

17. Can you define what Long Polling is?

Long polling is a method to maintain a persistent connection to the server. Long polling keeps the client’s connection intact and open till the server can transmit data to any client. The connection closes only after data is returned to a client, or when a connection timeout happens. 

18. What is DTD and what is the difference between PCDATA and CDATA in DTD?

DTD is short for Document Type Definition. It defines attributes, structure, and legal elements of XML documents.

PCDATA, or Parsed Character Data in the DTD, is the text that the XML parser will parse. Tags within the text are processed as markup, and the entities are expanded.

CDATA, or Character Data in the DTD, is the text that the XML parser will not parse. Tags within the text are not processed as markup, and the entities are not expanded.

19. What are the APIs that the HTML5 standard provides?

HTML5 incorporates a variety of APIs, such as:

• History API
• Constraint Validation 
• Application Cache
• Command API
• User Interaction
• Data Transfer
• Text Track 
• Media API

20. What is the best way to integrate different style sheets into a website? 

To style a single HTML element on the page, use Inline CSS in the style property. By incorporating CSS into the head portion of our HTML text, we may embed an internal stylesheet. In order to keep our CSS and HTML separate, we can also connect to an external stylesheet.

21. How do you optimize the loading time of your web application as a Web Developer?

6 Simple Methods for Boosting Page Loading Speed

1. Select a hosting solution that is optimized for performance.
2. Optimize and compress your images.
3. Reduce the number of redirects you use.
4. Cache your website's pages.
5. Activate browser caching.
6. CSS, JavaScript, and HTML should all be minified.

22. Define NPM (Node Package Manager). 

The word NPM (Node Package Manager) tends to come from when npm was first created as a package manager for Node.js. All npm packages are defined in package.json files. The package's contents

23. What are the different popup boxes that are available in JavaScript? 

Popup boxes are used in Javascript to display a message or notification to the user. In JavaScript, pop-up boxes are classified into three types:

• Alert boxes
• Confirm boxes
• Prompt boxes.

24. Explain the term “Scope” in JavaScript and write its different types.

The JavaScript variable accessibility is based on the current context of the code, which is referred to as scope.

The two scope kinds are local and global. Variables that are declared outside of a block are referred to as global variables. Local variables are those that are declared within a block.

25. Can you explain what AJAX is?

• AJAX stands for Asynchronous JavaScript and XML.
• AJAX is a technique for creating dynamic and fast-loading web pages.
• AJAX enables asynchronous web page updates by secretly sharing small bits of data with the server.

26. What do you mean by CDN (Content Delivery Network) in jQuery?

CDNs cache content such as web pages, images, and videos in proxy servers located near your physical location.

You may check your bank balance, download software, watch a movie, post on social media, or make purchases without waiting for the content to load.

27. Explain W3C (World Wide Consortium).

A global organization made up of member organizations is the World Wide Web Consortium (W3C), a full-time staff, and the general public that collaborates to develop Web standards.

28. What do you mean by CSS Selectors? Name a Few.

The first component of a CSS Rule is a CSS selector. It is a pattern of elements and other terms that tells the browser which HTML elements should be selected in order for the CSS property values contained within the rule to be applied to them.

29. In CSS, there are numerous different sorts of selectors. Give some examples.

CSS Element Selector, CSS Id Selector, CSS Class Selector, CSS Universal Selector, and CSS Group Selector are some examples of CSS selectors.

30. How do pseudo-classes work?

A selector's term that indicates the special state of the selected element is called a pseudo-class in CSS.

For example, when a user's pointer hovers over a button, the pseudo-class:hover can be used to select it, and the selected button can then be styled.

31. Why are media queries used in CSS?

You can use media queries to apply CSS styles based on the general type of a device, such as print.

Media queries serve the following purposes: CSS @media and @import at-rules can be used to conditionally apply styles.

32. State difference between Local Storage and Cookies.

• JavaScript uses cookies to read from and save user-related tiny data on the browser.
• Using JavaScript's Storage API, Local Storage enables you to read from and save user-related data on the browser.
• Learn about some of the key distinctions between local storage and cookies in this article to determine which is best for your websites.

33. What is the purpose of Canvas in HTML?

The HTML canvas element is employed to draw graphics in JavaScript on the fly. The canvas element only serves as a container for graphics. JavaScript is required.

34. What is the purpose of closures in JavaScript?

A closure is a function that has been bundled (enclosed) with references to its surrounding state (the lexical environment). In other words, a closure allows you to access the scope of an outer function from an inner function.

35. What is an event loop in Node JS?

An event loop is an endless cycle that waits for tasks, completes them, and then goes to sleep until other tasks come along.

The special state of the chosen element occurs when the call stack is empty or when there are no running tasks.

The event loop executes tasks from the event queue. We can use callbacks and promises in the event loop.

Interview Questions for MEAN Stack Developer

An open-source, free JavaScript-based technology, MEAN includes 4 JavaScript software stacks - Node.js., AngularJS, ExpressJS, and MongoDB:that are used to develop dynamic web applications and websites. Here are the most commonly-asked MEAN stack web development interview questions and answers:

36. What is a Blocking Code?

If an application needs to await an I/O (Input/output) operation for completion of its execution, the code that is responsible for the waiting is called a blocking code.

37. What is the CSS Grid System?

Integrating 2 key components, columns and rows, CSS Grid Systems allow for both horizontal and vertical content stacking in an easily manageable and consistent manner.

CSS Grid Systems include:

• Flexbox Grid
• Foundation
• Bootstrap
• Pure
• Simple Grid

38. What are Angular Route Guards?

Route guards or routing guards in Angular are interfaces that tell a router whether it should permit navigation to the requested route. Route guards make decisions based on the return value of false/true, which comes from the classes that implement the guard interfaces.

39. Can you compare MongoDB and SQL Databases?

Data is stored as columns, rows, tables, and records on SQL databases. The data storage takes place on a pre-defined model that is not elastic enough to support the needs of today's new-generation applications. MongoDB, on the contrary, adopts a flexible architecture that users can easily modify.

40. Are all the Object-Oriented Programming Principles supported in Typescript?

Yes, TypeScript supports and implements all 4 object-oriented programming principles, which are:

• Polymorphism
• Abstraction
• Inheritance
• Encapsulation

FAQs

1. How to become a web developer?

While there are no formal or specific requirements for becoming a web developer, a numerate degree in a subject. Additionally, you ought to be skilled in or have knowledge of the following components: User Experience (UX) and User Interface (UI).

2. What does a web developer do? 

Websites are created and maintained by web developers. They are also in charge of the site's technical aspects, such as performance and capacity, which are measures of a website's speed and capacity to handle traffic.

3. How much time does it require to learn web development?

Web development boot camps typically last 3-4 months and teach all of the skills required to qualify for a web developer job. Learning web development through online courses can take anywhere from a month to several years, depending on how much time you devote to your courses.

4. What should a web developer know?

To succeed as a Developer, you should be familiar with HTML, CSS, and JavaScript. The acquisition of these core web development abilities will serve as the basis and reasoning for communicating with programming languages.

5. Who should learn web development?

A web developer can be anyone. The acquisition of these core web development abilities will serve as the basis and reasoning for communicating with programming languages as long as you're passionate about the field and eager to learn.  

6. Do web developers use coding?

Web developers use coding languages 

• HTML
• CSS
• JavaScript
• Python

7. What is the average salary of a web developer in India? 

Web Developer salaries in India range from 1.0 Lakhs to 7.0 Lakhs per year, with an average annual salary of 3.0 Lakhs. Estimated salaries are based on the most recent 26k salaries received from Web Developers.

8. Why should you be hired for a web development internship?

Work placements are a great way to learn about your career field while also developing skills that will help you land one of the highest-paying jobs in the world in the future.

They also assist students in exploring their interests prior to pursuing a career and gaining experience in their chosen field.

9. State the difference between a web developer and a software developer

• A web developer is someone who works on web-based applications like websites, e-commerce, and mobile development.
• A software developer, on the other hand, will focus on creating software for the underlying operating system, network, or platform.
• The main distinction is the type of projects you might be assigned to work on.

10. How do you talk about web-development projects in an interview?

Mention a recent interesting or unique project you worked on to keep the interviewer interested in your response. Then, briefly go over the key points of your web development stages.

11. State different types of web development.

On the front end of web development.

• Front-end web development is in charge of how a website looks.
• Web development from start to finish
• Web development on the back end.
• Designer of websites.
• Web developer.
• Creator of content. Webmaster.

Get Started: Become a Full-Stack Web Developer in 9 Months!

The term stack encompasses products and technologies that constitute the backbone and technological ecosystem for creating and managing web applications. A stack, in practice, includes databases, application frameworks, runtimes, and client-side architectures. Depending on project requirements, full-stack developers use various front-end and back-end stack components, including Ruby on Rails, LAMP, MERN, and MEAN to ensure optimal efficiency. 

Full-stack web development is one of the top employment opportunities in the world today, both in terms of scope and demand. Several multinational companies are looking for full-stack web developers for their all-round knowledge of UI/UX, product testing via Minimum Viable Product (MVP) cycles, app development environments, and mobile-first solutions. 

If you are keen on pursuing a full-stack web development career, check out the industry-recognized Full Stack Developer - MERN Stack, offered by the world’s #1 online bootcamp and certification provider, Simplilearn, in association with the California Institute of Technology (Caltech) Center for Technology and Management Education (CTME).  

Simplilearn’s leading-edge full-stack web development training program teaches 30+ in-demand tools, and it provides access to 250+ hours of applied learning, twenty lesson-end and five phase-end projects, masterclasses from Caltech CTME faculty, online convocation by Caltech CTME Program Director, and capstone projects in four domains. Click here to get certified by the Caltech CTME.