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Top 50+ Web Development Interview Questions and Answers
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Top 50+ Web Development Interview Questions and Answers

Published On: April 4, 2024

“Web” stands for web pages, websites, or anything on the internet, while “development” refers to the process of creating these kinds of applications from the ground up. It includes creating and managing websites and web-based apps, including online stores like Flipkart, Amazon, Myntra, and many others, and social networking sites like Instagram, Facebook, LinkedIn, Twitter, and many more. 

You should expect web dev interview questions about your technical and soft skills and your proficiency as a web developer will be evaluated in the technical part. With our carefully curated list of the most important web development interview questions and professionally written answers, you’ll have a distinct advantage during your web developer interview. 

Basic Questions for Web Developer Interview Questions and Answers

Here are the basic questions for web developer interviews and they are useful for freshers.

1. Why is a namespace used in web development?

Methods, attributes, and other objects can be stored in a namespace, which is a basic global object. Because of its modular design, it makes code easier to use and prevents name conflicts for users.

2. Why is SVG utilized and what does it mean?

Scalable Vector Graphics is referred to as SVG. Vector-based visuals are shown on the web with its help. Its ability to render graphical content is dependent on the XML format. SVG allows the user to provide high-quality images because the graphical content is of an exceptional level.

3. What is HTML’s Canvas function for?

With the addition of Canvas to HTML5, users may now utilize JavaScript to create visuals on the fly.  provides many ways to draw paths, circles, boxes, pictures, and other shapes.

4. How do you speed up the loading of pages?

The speed at which a website loads its pages depends on a variety of factors. Nonetheless, some steps may be taken to significantly lower it. Below are their details: 

  • The decrease in the picture dimensions
  • Elimination of unnecessary widgets
  • HTTP encoding
  • Reduced lookups
  • Very little caching and redirection

5. What does CORS stand for?

Cross-Origin Resource Sharing is referred to as CORS. It’s a method that lets several requests for different resources from a domain outside the current request domain be made at the same time.

6. What are some of the newly included features in CSS3?

Numerous enhancements brought about by CSS3 have improved the overall framework’s usability and strength. Some of the newly introduced features that are now in high demand include: 

  • Rounded corners
  • Animation
  • Custom layout
  • Media queries

7. What does Responsive Web Design (RWD) with HTML and CSS mean?

The idea behind responsive web design is to make websites that adapt to different screen sizes without losing any content or tearing. The web page’s structure is automatically modified to optimize the viewing experience, depending on the device.

8. What types of CSS are in use?

There are now three primary forms of CSS:

Inline CSS: Supports the inclusion of CSS inline with HTML elements.

External CSS: This method adds an external CSS file to the HTML content.

Embedded CSS: Utilizes the <style> tag to add CSS styles.

9. What is the purpose of a selector in CSS?

Inline items that need to be styled employ a CSS selector in conjunction with a rule. Finding and choosing HTML elements based on criteria like name, ID, attribute, etc. is simple with the aid of selectors.

10. What are the popular web development technologies?

The popular web development technologies are HTML, CSS, JavaScript, SQL, Python, PHP, etc.

11. Why is grouping used in CSS3?

With just one declaration statement, users can reuse and apply the same CSS style element to many HTML elements thanks to grouping in CSS3.

A basic example of grouping is shown below: 

12. How does Webkit work in CSS3?

To show HTML and CSS elements across different web browsers, such as Chrome, Safari, and older versions of Opera, Webkit is a rendering engine used in CSS3. It offers the features required to generate web content and guarantee cross-platform consistency.

Recall that several browser engines exist besides Webkit, including Gecko (found in Mozilla Firefox), Presto (found in previous versions of Opera), and EdgeHTML (found in Microsoft Edge before it transitioned to Chromium).

13. What is involved in front-end development? 

The graphics you see on online pages where users can interact with certain web elements are known as front-end development. The primary tools used by the front end to generate interactive web pages are HTML, CSS, and JavaScript.

14. How is website performance improved by a CDN?

A content delivery network, or CDN, is required to improve website performance. It allows the user to download data from the closest servers and hosts the website’s resources across numerous servers.

15. What does web development backend mean?

The back end of a website refers to functions like server-side logic, database integration, and user authentication. ExpressJS and NodeJS can be used in tandem to construct the backend.

16. What does an HTML Doctype serve as?

Telling the browser what version of HTML the code is written in is the goal of the Doctype declaration in HTML. Additionally, it verifies that the page appears appropriately in the browser.

17. Describe how semantic HTML is used.

HTML tags give the user and the browser a clear explanation of what they signify. 

Non-semantic elements include <div> and <span>, which reveal nothing about their contents.

Semantic elements, such as <form>, <table>, and <article>, are defined explicitly in terms of their content.

18. How do child selectors work in CSS?

In CSS, child selections are useful for focusing on particular items that are offspring of another element. They can only be applied styles to or actions taken on immediate child components, and are indicated by the “greater than” mark (>).

Child selectors are helpful for more accurate CSS targeting, granular style creation, and managing the look of particular child elements inside a parent container.

19. How does CSS3 make it easier to implement rounded borders?

The <border-radius> attribute in CSS3 enables the creation of elements with attractive rounded corners. This is easily applicable on all four sides or as needed.

For each of the four corners, the <border-radius> property includes four attributes: 

20. What makes up the CSS box model’s components?

The CSS box model represents an entity that has all of the HTML content contained inside a box or button element. 

There are four parts:

Border: Indicates the material and cushioning surrounding the border. 

Content: This describes the real stuff that will be shown.

Margin: This denotes the box element’s uppermost layer.

Padding: Describes the void surrounding the component.

21. What are some of the characteristics of CSS3 transitions? 

Transitions in CSS3 are user-friendly and offer quick and effective animation effects. They have four primary properties:

  • transition-delay
  • transition-duration
  • transition-property
  • transition-timing-function

22. How may pseudo-classes be used in CSS?

To alter an element’s style as its state changes, pseudo-classes are an often used CSS approach. The use of a pseudo-class can be seen in many different contexts:

  • If the mouse passes over the element, the style will change.
  • For animations that are out of focus
  • To supply styles for outside connections 

23. What function do media queries perform in CSS3?

CSS styles are defined using media queries and are responsive to different viewing window sizes and shapes. They are employed to modify the subsequent entities: 

  • Height
  • Width
  • Viewport
  • Resolution
  • Orientation

24. Why are external style sheets preferred?

External style sheets offer developers a plethora of benefits. Some of the advantages are:

  • Classes are reusable indefinitely.
  • They enable style management across several documents using a single file.
  • Using selectors and grouping makes applying styles simple.

25. A development style called “long polling” is used to simulate data pushing from a server to a client computer.

The client requests data from the server while extended polling is enabled, and the server responds. Only once the timeout requirements are satisfied or the data is transmitted to the client will the connection time out.

26. Which data types are available in JavaScript?

JavaScript is compatible with the subsequent data types, such as 

  • Boolean
  • Number
  • Object
  • Undefined
  • Null
  • String
  • Function

27. What is a web application framework?

 A pre-built collection of libraries known as a web framework, or WAF, aids the developer in building the website. It contains codes, such as authentication, that are standard across several websites. By giving the developer the code for the comma section, it frees them up to concentrate on the website’s distinctive feature.

28. What is the purpose of WebSockets?

Real-time, event-driven communication between a client and server can be enabled via WebSockets. Bidirectional communication is possible with WebSockets, allowing data to be sent back and forth between the client and server at any time.

29. In what ways do CSS preprocessors improve CSS coding?

The capabilities of basic CSS are expanded by CSS preprocessors such as SASS and LESS. They layer functions for intricate processes, add variables for reused values, and arrange code. These enhancements increase the effectiveness, reusability, and maintainability of CSS writing. Compiling CSS preprocessors results in ordinary CSS that is compatible with browsers.

30. How may JavaScript be used to modify an element’s classes or styles?

The following syntax in JavaScript can be used to quickly change the classes and styles of an element:

Modify styles: document.getElementById(“input”).style.fontSize = “10”;

Modify class: document.getElementById(“button”).className = “classname”;

31. What is the difference between HTML and XHTML?

In HTML, there are no case-sensitive, open-ended tags that can be used, and attributes can be used without a question mark.

In XHTML, tags should be in lowercase, they should be closed once opened, and attributes must be enclosed in double-quotes.

32. Differentiate between local storage and cookies

Cookie data is available to both the client and the server. It has an expiration date, after which it is erased.

Data is exclusively kept on the client-side local browser; unless it is purged explicitly, it never expires in local storage.  

33. What is z-index in CSS?

The CSS property Z-index is used to specify the arrangement of components on a page. A higher-order element will appear before a lower-order element according to the system’s order indices. It only applies to positioned elements, that is, elements that have the position property required. 


34. Explain pagination. How might pagination be put into practice?

A website’s pagination is only a list of pages. These pages are linked together and present users with comparable content. A straightforward illustration is the page picker on an e-commerce website, which enables customers to scroll up and down on numerous pages to view the products instead of just one.

The following code can be used to implement it in CSS3 with ease: 

35. Differentiate between localStorage and sessionStorage objects. 

  • Data that is stored has no expiration date and is not erased when the window closes.
  • The item is only good for one session, and as soon as the window is closed, it is instantly removed.

36. Differentiate between canvas and SVG.

While it does not allow event handlers and is resolution-dependent, Canvas is a good choice for small-scale rendering applications.

Whereas, SVG is resolution-independent; it supports event handlers, and it performs better for large-scale rendering applications.

37. What is the difference between SOAP and REST?

  • SOAP is the web development protocol, while REST is an architectural platform. 
  • SOAP works well with XML, while REST works with XML, HTML, and plain text.
  • SOAP can’t use REST but REST can make use of SOAP.

Ensure you are thorough with these basic questions for web developer interview to get succeed in your first attempt.

Senior Web Developer Interview Questions

The following includes senior web developer interview questions and they are useful for experienced professionals. Even if you are a fresher or intermediate candidate, we still advise you to review them.

38. What popup box types are available in JavaScript?

In JavaScript, three different kinds of dialog windows are used:

Alert: Shows a message to users along with an “OK” button.

Confirm: Presents a popup with “OK” and “Cancel” buttons to the users

Prompt: Displays user input with buttons labeled “OK” and “Cancel.” 

39. What does it mean to be a JavaScript variable’s scope?

The term “scope” describes how easily accessible functions and underlying variables are within the operating system. In JavaScript, two scopes are supported:

Local scope: In this case, variables and functions that are declared inside the same function are only accessible from within it, not from the outside. Take a look at this instance:

Global scope: A variable that is marked as global is accessible from any location within the application. Take a look at this instance:

var globalVariable = “This is a Global variable”;

40. Why does JavaScript frequently use <this> keyword?

To access the current object in a program, use the <this> keyword. The keyword is used to reference the relevant variable or object, and this object is contained within a method.

41. What benefits does jQuery offer when utilizing a Content Delivery Network (CDN)?

As CDNs have so many benefits to offer consumers, they are employed extensively in jQuery.

  • The server’s load is significantly reduced via CDNs.
  • They offer significant savings in bandwidth usage.
  • Optimizations allow for faster loading of jQuery frameworks.
  • The caching capacity of CDNs enables faster load times. 

42. How is CSS coding benefited by the BEM methodology? 

CSS class names can be organized using BEM (Block Element Modifier). By naming classes after the HTML elements they style, it facilitates code organization. This illustrates how structure and appearance are related. By giving class names greater significance, BEM enhances the readability, maintainability, and scalability of CSS.

43. What is continuous integration (CI)?

Developers that use continuous integration routinely integrate code updates into a common repository. With every code update, automated builds and tests are performed to identify problems early. Frequent testing and code integration enhance software quality and accelerate delivery. 

44. What distinguishes <onDocumentReady> from <window.onload>?

A page does not invoke the <window.onload> event until all of the CSS and image styles have been loaded. When rendering a web page, the event does cause a little delay. With the <onDocumentReady> event, the event action will start as soon as the DOM is initialized. This guarantees a decrease in action delays.

45. How does JavaScript handle type conversion?

JavaScript supports type conversion automatically. It is easy to send a function as an argument to another function because it is loosely typed.

Values are automatically transformed to the appropriate data type, ensuring that there are no errors or warnings related to data types.

46. How are JavaScript comments used?

There are two ways that comments can be added to JavaScript code. Both single- and multi-line comments are allowed.

Single-line statement: To insert a single-line comment, use “//”.


// This is a comment with a single line.

Multi-line comments: They can be added using the notation “/* */”. 


/* This

is a



47. In JavaScript, what are undefined and undeclared variables?

Undefined variables are those that have already been declared but have not yet been initialized. An undeclared variable, on the other hand, is utilized in a program without having been declared.


48. What is the JavaScript form submission procedure?

JavaScript users can submit forms with ease by using the following method: 


In this case, ‘0’ represents the form’s index.

49. What does JavaScript’s <defer> attribute mean?

The <defer> is applied as a property of the boolean type. It is used to wait for the parser to fully load and initialize the page before starting the JavaScript code on a web page.

50. What is the purpose of jQuery’s each() function?

jQuery’s each() function is used to iterate over a group of elements and apply a predetermined action to each one individually. It streamlines the procedure for applying changes or operations to several elements clearly and efficiently.

51. If a jQuery Event Handler returns false, what happens?

A jQuery event handler that returns false disables the event’s normal action and stops it from spreading further. When specific requirements aren’t met, this can be used to reverse the completion of tasks like navigating links or submitting forms.

52. What is pair programming? 

Pair programming is a cooperative method of developing software where two programmers collaborate on the same project. While the other person, referred to as the “observer” or “navigator,” actively reviews the code being written, the first person, known as the “driver,” writes the code. They alternate responsibilities frequently, encouraging collaboration, information exchange, and high-quality code.

53. Why is the $() function in jQuery used?

jQuery’s $() function is used to choose and work with HTML elements. Using a clear and simple syntax, it offers a handy approach to changing specific element’s characteristics, styles, content, and event handlers.

54. Which kinds of CDNs does jQuery support?

Two popular CDNs that work with jQuery are:

Microsoft: used for jQuery AJAX CDN loading

To load jQuery from the Google Libraries API, use Google. 

55. What are the benefits of server-side rendering (SSR) for SEO?

Web pages are created on the server and then transmitted to the browser via server-side rendering (SSR). This improves SEO by making material instantly accessible to search engine crawlers for indexing. SSR ensures that web page content is completely accessible to and readable by search engines.

56. Describe the architecture of microservices.

Instead of creating a single, massive application, microservice design divides an application into smaller, independent services. Every microservice can be independently developed and updated, and each one focuses on a certain capability. This modular design makes it easier to create, scale, and maintain applications.

57. What role does Git play in web development?

Git keeps track of all code modifications and enables collaboration among developers without erasing one another’s work. Maintaining code history and combining updated code from several contributors facilitates collaboration. Due to its support for parallel workstreams and source code versioning, Git helps remote teams create software quickly and effectively.

58. What is the difference between a span tag and a div tag in HTML? 

To designate a section of a web page, use the div and span tags. On a web page, spans are inline elements and divs are block-level elements. The webpage’s block sections are displayed using the <div> element, while the inline sections are displayed using the <span> tag. 


<div>Web Development Provides A Bright Career<span>Learn at SLA<span></div>

Span Tag

Div Tag

Paragraphs and inline components will both use the span tag.

Elements at the block level are enclosed with div tags.

This tag is usually used to draw attention to a single word on a webpage, or a specific portion of a line.

It is typically utilized or connected to draw attention to a certain area of the webpage. 

We utilize a particular color code in this tag to draw attention to the HTML information.

To draw attention to the HTML content within this tag, borders of a defined color for both height and width are used.

The span tag will not display on a new line because it does not support the align attribute.

When the align attribute is supported, the div tag will move to a new line.

59. What does JavaScript ‘Type Coercion’ mean?

The process of implicitly or automatically changing values from one data type to another is referred to as type coercion. You could, for example, convert a boolean to a number, a string to a number, or a number to a string.

Example: Converting Numbers to Strings


This example demonstrates how JavaScript transformed the number 5 into a string and combined the values to produce 550.

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