HTML Interview Questions and Answers (2025)

By TheEasyMaster | Published on 18 January 2025
html interview

Table of Contents

1. What is HTML?

HTML (HyperText Markup Language) is the standard language used to create and structure content on the web. It defines the structure of web pages using tags and attributes.

2. What are the different types of HTML elements?

HTML elements can be divided into:

  • Block-level elements: These elements take up the full width and start on a new line (e.g., <div>, <p>, <h1>).
  • Inline elements: These elements take only the necessary width and do not start on a new line (e.g., <span>, <a>, <img>).

3. Explain the structure of an HTML document.

A basic HTML document structure includes:

  • <!DOCTYPE html>: Declaration defining the document type.
  • <html>: Root element.
  • <head>: Contains meta information about the document (e.g., title, character set).
  • <body>: Contains the visible content of the web page (e.g., text, images, links).

4. What is the difference between <div> and <span>?

  • <div> is a block-level element used for grouping and structuring content, and it takes up the full width of its container.
  • <span> is an inline element used for styling small sections of content without disrupting the flow of text.

5. What are HTML attributes?

Attributes provide additional information about an element. They are written inside the opening tag. Examples include href in <a> tags, src in <img>, and alt in <img>.

6. What are semantic HTML tags?

Semantic tags are HTML tags that convey meaning about the content they enclose. These help search engines and developers understand the structure of a web page. Examples include <header>, <footer>, <article>, and <section>.

7. What is the purpose of the <meta> tag?

The <meta> tag provides metadata about the HTML document, such as character encoding, author, viewport settings, and SEO-related information (e.g., description, keywords).

Use the <a> tag with the href attribute to create a hyperlink

<a href="https://example.com">Visit Example</a>

9. What is the difference between GET and POST methods in forms?

  • GET: Sends form data as part of the URL (visible in the browser’s address bar). Suitable for retrieving data.
  • POST: Sends form data in the HTTP request body (not visible in the address bar). Suitable for submitting sensitive data.

10. What is the <picture> element in HTML5?

The <picture> element allows you to define multiple image sources based on different conditions, such as screen width or image resolution, helping to create responsive images. Example:

<picture>
  <source srcset="image-small.jpg" media="(max-width: 600px)">
  <img src="image-large.jpg" alt="Responsive Image">
</picture>

11. What is the <canvas> element in HTML5?

The <canvas> element is used for drawing graphics, animations, and other visual content using JavaScript. Example:

<canvas id="myCanvas" width="200" height="200"></canvas>
<script>
  var canvas = document.getElementById("myCanvas");
  var ctx = canvas.getContext("2d");
  ctx.fillStyle = "blue";
  ctx.fillRect(20, 20, 150, 100);
</script>

12. What is the purpose of the alt attribute in the <img> tag?

The alt attribute provides alternative text for an image if it cannot be displayed. It also helps with SEO and accessibility for screen readers. Example:

<img src="logo.jpg" alt="Company Logo">

13. What are ARIA roles in HTML?

ARIA (Accessible Rich Internet Applications) roles help improve web accessibility for users with disabilities. They describe the role of an element to assistive technologies. Example:

<div role="alert">This is an important message</div>

14. How do you create a form in HTML?

A form is created using the <form> tag, with various input elements like <input>, <textarea>, and <button>. Example:

<form action="/submit" method="post">
  <label for="name">Name:</label>
  <input type="text" id="name" name="name">
  <input type="submit" value="Submit">
</form>

15. What are the new input types introduced in HTML5?

HTML5 introduced several new input types, such as:

  • email: For email addresses.
  • url: For URLs.
  • date: For date input.
  • tel: For telephone numbers.
  • range: For numeric ranges.

16. What is the difference between class and id attributes?

  • class: Used to assign styles or group elements, and can be used multiple times in a document.
  • id: Used to uniquely identify a single element, and should only be used once per page.

17. What are the benefits of using semantic tags for SEO?

Semantic tags help search engines understand the content structure of a page. They also improve the accessibility of a website by clearly defining different sections, leading to better indexing and ranking.

18. What is the <!DOCTYPE> declaration in HTML?

The <!DOCTYPE> declaration tells the browser which version of HTML to use for rendering the document. For HTML5, it’s <!DOCTYPE html>.

19. What are HTML Data Attributes (data-*)?

HTML data attributes allow you to store custom data on any element. The data can be accessed via JavaScript. Example:

<div data-user-id="12345">User Info</div>

20. What is the role of the <meta charset="UTF-8"> tag?

The <meta charset="UTF-8"> tag specifies the character encoding for the document. UTF-8 is a common encoding that supports many languages and special characters.

21. What is the difference between the <script> and <noscript> tags in HTML?

  • <script>: Used to include or reference JavaScript code. It can be placed in the <head> or <body> section.
  • <noscript>: Used to define content that is displayed if the browser does not support JavaScript or if it’s disabled by the user.

22. How can you include an external CSS file in an HTML document?

Use the <link> tag in the <head> section to include an external CSS file

<link rel="stylesheet" href="styles.css">

The target="_blank" attribute opens the linked document in a new tab or window. Example:

<a href="https://example.com" target="_blank">Open in new tab</a>

24. What is the rel="noopener noreferrer" attribute, and why is it used with target="_blank"?

The rel="noopener noreferrer" attribute ensures better security by preventing the new tab from gaining access to the originating page’s window object and stopping the referrer from being sent to the linked page. It’s important when using target="_blank" to avoid security risks.

25. What is the use of the <base> tag in HTML?

The <base> tag specifies the base URL for all relative URLs in a document. It is placed inside the <head> section.

<base href="https://www.example.com/">

26. Explain the concept of the “Document Object Model (DOM)” in relation to HTML.

The DOM represents the HTML document as a tree structure, where each HTML element is a node. It allows JavaScript to access and manipulate the structure, style, and content of the web page dynamically.

27. What is the role of the <iframe> tag in HTML?

The <iframe> tag is used to embed another HTML page within the current page. Example:

<iframe src="https://example.com" width="600" height="400"></iframe>

28. What are the new input attributes in HTML5 that help with form validation?

HTML5 introduced several input attributes for form validation:

  • required: Ensures the user cannot submit the form without filling in the field.
  • pattern: Specifies a regular expression to validate the input.
  • min and max: Defines the range for input values.
  • maxlength: Limits the number of characters that can be entered.

29. What is the difference between the <b> and <strong> tags in HTML?

  • <b>: Represents bold text purely for styling purposes.
  • <strong>: Represents text with strong emphasis, and it is typically displayed as bold. It also conveys meaning to assistive technologies, improving accessibility.

30. What is the viewport meta tag and how does it affect responsive design?

The viewport meta tag defines the visible area of a webpage on different devices. It is essential for responsive web design and allows the page to scale appropriately on mobile devices:

<meta name="viewport" content="width=device-width, initial-scale=1.0">

31. What are HTML entities and why are they used?

HTML entities are special codes used to represent characters that cannot be typed directly in HTML (e.g., <, >, &, ", etc.). They are written as &name; or &#code;. Example: &lt; for <, &gt; for >, &amp; for &.

32. What is the <head> section in HTML and what elements can it contain?

The <head> section contains meta-information about the HTML document, such as:

  • <title>: Specifies the title of the document.
  • <meta>: Provides metadata like character set, author, and viewport settings.
  • <link>: Used to link external resources (e.g., CSS files).
  • <style>: Contains internal CSS styles.
  • <script>: Used to include or reference JavaScript files.

33. What is the difference between the <ol> and <ul> tags?

  • <ol>: Represents an ordered (numbered) list.
  • <ul>: Represents an unordered (bulleted) list.

Example:

<ol>
  <li>First item</li>
  <li>Second item</li>
</ol>
<ul>
  <li>First item</li>
  <li>Second item</li>
</ol>

34. What are HTML global attributes?

Global attributes can be applied to most HTML elements. Common global attributes include:

  • id: Specifies a unique identifier for the element.
  • class: Specifies one or more class names for the element.
  • style: Specifies inline CSS styles.
  • title: Provides additional information about an element, usually displayed as a tooltip.
  • data-*: Used for custom data attributes.

35. What is the <mark> element in HTML?

The <mark> tag is used to highlight text, indicating that it has special relevance or matches a search term. Example:

<p>This is <mark>important</mark> text.</p>

36. What is the loading="lazy" attribute in HTML?

The loading="lazy" attribute enables lazy loading of images, iframes, and other media, meaning they are only loaded when they enter the viewport, improving page performance. Example:

<img src="image.jpg" loading="lazy" alt="Lazy loaded image">

37. What is the <template> tag used for in HTML?

The <template> tag is used to define a block of HTML that is not rendered immediately but can be cloned and inserted into the document later via JavaScript. It’s useful for client-side templating.

38. What is the <progress> element in HTML?

The <progress> element represents the progress of a task. It is typically used for displaying a progress bar. Example:

<progress value="70" max="100">70%</progress>

39. What are the advantages of using the <aside> tag in HTML?

The <aside> tag is used for content that is related to the main content but could be considered separate, such as sidebars, pull quotes, or additional information. It helps with page organization and semantic meaning.

40. What is the <footer> tag used for in HTML?

The <footer> tag defines the footer of a webpage or section. It typically contains copyright information, contact links, and other metadata relevant to the content.

Additional Resources

For those interested in expanding their skills with APIs, check out our Top 10 Free APIs for Practice in 2025 and improve your JavaScript mastery with our Master ES6 JavaScript – Complete Guide at Master ES6 JavaScript – Complete Guide.

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