Top 30+ Web Developer Interview Questions With Answers

The interviewer wants to know your understanding of what Web Development involves and its components.

Sample Answer:

Web Development involves creating and maintaining websites or web applications. It includes Front-end Development (what users see) and Back-end Development (how the site works behind the scenes). It combines design, coding, database work, and performance optimisation to deliver full-functioning websites.

The interviewer wants to assess your technical skills and familiarity with essential Web Development languages.

Sample Answer:

“I have experience with HTML, CSS, and JavaScript for Front-end Development. On the back-end, I've worked with Node.js and Express.js. I’ve also handled databases using MongoDB and MySQL. For version control, I use Git and GitHub.”

The interviewer wants to evaluate your knowledge of modern HTML standards and best practices.

Sample Answer:

Semantic HTML elements describe their meaning to both the browser and the developer. Tags like

The interviewer wants to check your understanding of how different HTML elements behave in a webpage layout.

Sample Answer:

Block-level elements take up the full width and start on a new line like

The interviewer wants to know how well you understand type handling and conversion in JavaScript.

Sample Answer:

Type coercion in JavaScript is when the language automatically converts values from one type to another. For example, '5' + 2 becomes '52' (string), but '5' * 2 becomes 10 (number). This flexibility can be helpful but also tricky if not handled properly.
 

The interviewer wants to understand your teamwork experience in a collaborative coding environment.

Sample Answer:

“Pair programming is when two developers work together on one computer. One writes the code (driver), and the other reviews each line (navigator). It helps improve code quality, catch bugs early, and share knowledge across the team.”

The interviewer wants to check if you know the broader scope of the role beyond just writing code.

Sample Answer:

Web Developers are responsible for designing, building, testing, and maintaining websites. This includes writing clean code, optimising performance, ensuring mobile responsiveness, fixing bugs, and collaborating with designers, Content Creators, and other developers.

The interviewer wants to test your knowledge of modern web protocols and performance improvements.

Sample Answer:

HTTP/2 is faster and more efficient. It supports multiplexing (multiple requests in one connection), header compression, and server push. These improvements reduce latency, improve loading speed, and offer a better user experience.

The interviewer wants to know if you understand web standards and how they differ.

Sample Answer:

HTML is forgiving of mistakes and doesn’t require strict syntax. XHTML follows XML rules, so it’s stricter that every tag must be closed, lowercase, and properly nested. XHTML is more suitable when clean, structured code is a must.

The interviewer wants to understand your motivation and passion for Web Development.

Sample Answer:

“I’ve always enjoyed problem-solving and creating things that people interact with. Web Development lets me combine creativity with logic. It’s exciting to build something visual that also solves real problems for users.”

The interviewer wants to assess if your work style matches their company culture.

Sample Answer:

“I do best in collaborative, feedback-driven environments where learning is encouraged. I like working with teams that share ideas openly and support one another in delivering great products.”

The interviewer wants to check your knowledge of responsive design and user behaviour.

Sample Answer:

Mobile design requires responsive layouts, touch-friendly interactions, and performance optimisations for slower networks. Desktop designs have more space, so they often include more complex interfaces and rely on keyboard and mouse interactions.

The interviewer wants to know how you handle performance optimisation.

Sample Answer:

“I compress and optimise images, use minified CSS/JS, reduce HTTP requests, and leverage caching. I also use lazy loading for media and CDNs for faster content delivery.”

The interviewer wants to check if you understand how JavaScript interacts with HTML.

Sample Answer:

The DOM (Document Object Model) is a representation of the HTML document as a tree. It allows JavaScript to interact with elements, and change content, styles, and structure dynamically without reloading the page.

The interviewer wants to see how well you handle asynchronous operations.

Sample Answer:

A promise is a JavaScript object that represents a value that may be available now, later, or never. It helps manage asynchronous code by using .then() for success and .catch() for error handling.
 

The interviewer wants to test your understanding of JavaScript scopes and function behaviour. 

Sample Answer:

A closure is a function that has access to its outer function's scope even after the outer function has finished executing. It allows functions to keep variables private and is often used in scenarios like data encapsulation or event handlers.

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The interviewer wants to know how you manage scope and avoid polluting the global namespace.

Sample Answer:

An IIFE (Immediately Invoked Function Expression) is a function that runs as soon as it is defined. It’s used to create a private scope and is written like this:

The interviewer wants to see your understanding of modern API design principles.

Sample Answer:

REST (Representational State Transfer) is a design pattern for building APIs that use standard HTTP methods like GET, POST, PUT, and DELETE. It allows communication between systems in a stateless, scalable, and flexible way.

The interviewer wants to assess your knowledge of web security and cross-origin policies.

Sample Answer:

CORS (Cross-Origin Resource Sharing) is a security feature in web browsers that restricts requests to different domains unless explicitly allowed by the server using headers like Access-Control-Allow-Origin.

The interviewer wants to evaluate your database knowledge and when to use each type.

Sample Answer:

SQL databases (like MySQL) use structured tables and are great for complex queries. NoSQL databases (like MongoDB) use flexible formats like JSON and are better for large-scale or real-time applications that require quick access and high scalability.

The interviewer wants to know your experience with version control systems.

Sample Answer:

Git is a version control system used to track changes in code. It allows multiple developers to work on the same project without conflicts. It helps manage code versions, roll back to previous states, and collaborate efficiently using platforms like GitHub.

The interviewer wants to understand how you integrate external data or services into web apps.

Sample Answer:

Web APIs allow communication between applications over the internet. For example, you can use a weather API to display real-time temperature data on a website. APIs often use JSON and HTTP methods for data exchange.

The interviewer wants to know your understanding of version control systems and how you manage code changes in projects.

Sample Answer:

Git is a distributed version control system that helps developers track changes in code, collaborate with team members, and manage different versions of a project. It’s widely used to streamline development, resolve conflicts, and maintain a history of changes, especially when working on large or collaborative projects.

The interviewer wants to test your grasp of asynchronous programming and how Node.js handles I/O operations.

Sample Answer:

The event loop in Node.js handles asynchronous tasks. It allows non-blocking operations by placing long-running tasks (like file I/O) in the background and continues executing other code. When the task is complete, its callback is added to the queue and executed.

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The interviewer wants to see how you manage client-side storage.

Sample Answer:

HTML5 Web Storage provides two methods: localStorage for data that persists across sessions and sessionStorage for data that lasts only until the browser is closed. Both store key-value pairs in the browser without needing server interaction.

The interviewer wants to know how you improve site performance and user experience.

Sample Answer:

“I use techniques like code splitting, lazy loading, compressing files, caching strategies, and CDNs. I also remove unused code and reduce dependencies to make sure users get fast-loading responsive websites.”

The interviewer wants to assess your CSS knowledge, especially advanced selectors.

Sample Answer:

Pseudo-classes define the special state of an element, like :hover, :focus, or :nth-child(). They let you style elements based on interaction or position without needing extra classes or JavaScript.

The interviewer wants to test your understanding of advanced HTML features.

Sample Answer:

The element lets you draw graphics using JavaScript. It’s commonly used for games, visualisations, and custom animations by providing a blank drawing surface you can control with code.

The interviewer wants to know how you handle CRUD operations in APIs.

Sample Answer:

RESTful services use HTTP methods like:

1) GET: Fetches or retrieves data from the server without modifying it.

2) POST: Sends new data to the server to create a resource.

3) PUT: Updates or replaces existing data on the server.

4) DELETE: Removes a specified resource from the server.

These methods follow standard conventions for managing resources efficiently.

The interviewer wants to evaluate your communication and collaboration skills.

Sample Answer:

“Yes, I regularly interacted with clients to gather requirements, present prototypes, and explain project updates. It helped align our work with their goals and build trust through clear communication.”