10 Must Ask HTML Interview Questions For Hiring Managers

Posted on April 28 2024 by Interview Zen Team

Introduction

HTML (HyperText Markup Language) is the foundation of web development, an important skill for any software engineer stepping into the web development field. It is used to create and design web pages, combining text, images, and other multimedia content into a coherent format that browsers can display.

According to W3Techs, HTML5 is used by 96.9% of all websites in the world that use a markup language, making it an important language in the web development landscape. Its simplicity and versatility make it an excellent skill for aspiring web developers.

The goal of this article is to provide hiring managers with a set of essential HTML interview questions. These HTML interview questions are selected to cover various HTML topics, from basic to advanced, ensuring a comprehensive evaluation of a candidate’s HTML expertise.

In this article, we will explain what HTML is and provide the 10 must ask HTML interview questions. These HTML interview questions are designed for hiring managers to assess the developer’s expertise in HTML.

What is HTML?

HTML, standing for HyperText Markup Language, is the standard language used to create and design documents on the World Wide Web. It defines the structure and layout of a web document using a variety of tags and attributes. These tags label pieces of content such as “heading,” “paragraph,” “table,” and so on, making it possible for web browsers to display text, links, images, and other media on web pages in a structured and coherent manner.

According to Statista, HTML is the 2nd (52.97%) most-used programming language among developers worldwide as of 2024. This statistic highlights HTML’s extensive and enduring relevance in the tech world.

History

The inception of HTML can be traced back to 1989 when Tim Berners-Lee, a British computer scientist, proposed an internet-based hypertext system. HTML was developed to meet the need for a language that could describe the structure of information documents and link them to one another.

The first documented version of HTML was HTML 2.0, published in 1995, but HTML 4.01, released in 1999, brought it widespread adoption and standardization. In 2014, HTML5 was officially finalized, introducing a host of new features aimed at making HTML more powerful and interactive.

Key Features

  • Structure: HTML provides a clear structure to web documents, using elements and tags that define parts of a page, such as headings, paragraphs, lists, links, and more.
  • Multimedia Integration: It allows the embedding of images, audio, and video in the web pages, making the web a multimedia-rich platform.
  • Interactivity: HTML forms enable user interaction and data submission, enhancing the dynamic capabilities of web applications.
  • Accessibility: It supports accessibility standards, ensuring that web content is accessible to users with disabilities.

Top 10 Must-Ask HTML Interview Questions

1. What is the DOCTYPE declaration in HTML?

The DOCTYPE declaration is an instruction to the web browser about what version of HTML the page is written in. It must be the very first thing in your HTML document, before the <html> tag.

Example Answer: “The DOCTYPE declaration defines the document type and HTML version. For HTML5, we use <!DOCTYPE html>. It helps browsers render the page correctly and triggers standards mode instead of quirks mode.”

2. What is the difference between HTML elements and tags?

Understanding the distinction between elements and tags is fundamental to HTML comprehension.

Example Answer: “HTML tags are the markup symbols (<p>, </p>), while HTML elements include the opening tag, content, and closing tag together (<p>Hello World</p>). Tags are the syntax, elements are the complete structure.”

3. Explain the difference between <div> and <span> elements.

This question tests understanding of block-level vs inline elements.

Example Answer: “<div> is a block-level element that creates a new line and takes full width, while <span> is an inline element that doesn’t break the line and only takes necessary width. <div> is for grouping block content, <span> for styling inline content.”

4. What are HTML5 semantic elements?

Semantic elements provide meaning to the structure of web pages.

Example Answer: “HTML5 semantic elements like <header>, <nav>, <main>, <article>, <section>, <aside>, and <footer> provide meaning to the content structure. They improve accessibility, SEO, and code readability compared to generic <div> elements.”

Basic but essential HTML functionality.

Example Answer: “Use the <a> tag with the href attribute: <a href='https://example.com'>Link text</a>. You can link to external sites, internal pages (href='page.html'), email addresses (href='mailto:[email protected]'), or page sections (href='#section-id').”

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

This tests understanding of CSS selectors and HTML attributes.

Example Answer: “id is unique and should only be used once per page (id='unique-element'), while class can be used multiple times (class='reusable-style'). id has higher CSS specificity and can be used for JavaScript targeting and page anchors.”

7. Explain HTML forms and their important attributes.

Forms are crucial for user interaction.

Example Answer: “HTML forms collect user input using <form> element with attributes like action (where to send data), method (GET/POST), and enctype (encoding type). Form controls include <input>, <textarea>, <select>, and <button> elements.”

8. What are HTML5 input types?

HTML5 introduced many new input types for better user experience.

Example Answer: “HTML5 added input types like email, url, tel, number, date, time, color, range, and search. These provide better validation, mobile keyboards, and user interface elements automatically.”

9. How do you optimize images in HTML?

Image optimization is crucial for web performance.

Example Answer: “Use appropriate formats (JPEG for photos, PNG for graphics, WebP for modern browsers), include alt attributes for accessibility, set width and height to prevent layout shift, use loading='lazy' for performance, and consider responsive images with <picture> element.”

10. What is the difference between <script> tag placement in <head> vs <body>?

Script placement affects page loading and performance.

Example Answer: “Scripts in <head> block HTML parsing and delay page rendering. Scripts in <body> (especially before closing </body>) allow HTML to load first. Use async or defer attributes for non-blocking script loading: defer maintains order, async executes immediately when loaded.”

Conclusion

These HTML interview questions cover fundamental concepts that every web developer should understand. When interviewing candidates, look for clear explanations, practical examples, and understanding of best practices. A strong HTML foundation is essential for any web development role, as it forms the basis for more advanced technologies like CSS and JavaScript.

Remember that the best candidates will not only know the technical answers but can also explain the reasoning behind HTML best practices and their impact on accessibility, SEO, and user experience.

For hiring managers conducting technical interviews, consider using Interview Zen’s platform to create structured HTML assessments and monitor candidate performance in real-time during coding interviews.