2026

HTML5 Interview Questions 2026

A current, 2026 snapshot of the HTML5 interview questions worth knowing — kept up to date as frameworks and best practices evolve, so you prepare with what companies are actually asking in 2026.

60Questions14Beginner13Intermediate33Senior

60 HTML5 questions

  1. 1What are Web Workers?Intermediate
  2. 2What is the 'SVG' element and how is it used in HTML5?Intermediate
  3. 3What is the purpose of the <details> and <summary> tags?Intermediate
  4. 4Explain the 'defer' and 'async' attributes for <script> tags.Intermediate
  5. 5What is the 'datalist' element?Intermediate
  6. 6What is the Geolocation API?Intermediate
  7. 7What is the purpose of the <audio> and <video> tags?Intermediate
  8. 8Explain HTML5 Drag and Drop API.Intermediate
  9. 9What is the HTML5 Canvas element used for?Intermediate
  10. 10Explain the difference between LocalStorage and SessionStorage.Intermediate
  11. 11What is the purpose of the <time> tag?Beginner
  12. 12Explain the <progress> and <meter> elements.Beginner
  13. 13What does the 'placeholder' attribute do?Beginner
  14. 14What is the purpose of the <mark> tag?Beginner
  15. 15What is the difference between <nav> and a standard <ul> list?Beginner
  16. 16Explain the <figure> and <figcaption> elements.Beginner
  17. 17What is the purpose of the <main> tag?Beginner
  18. 18What are the new input types introduced in HTML5?Beginner
  19. 19Explain the difference between <section> and <article>.Beginner
  20. 20What is the purpose of the <!DOCTYPE html> declaration in HTML5?Beginner
  21. 21HTML5 Interview Question 2 (Free)Intermediate
  22. 22HTML5 Interview Question 5 (Free)Intermediate
  23. 23HTML5 Interview Question 4 (Free)Beginner
  24. 24HTML5 Interview Question 3 (Free)Senior
  25. 25HTML5 Interview Question 1 (Free)Beginner
  26. 26Explain 'Battery Status API' (and why it's mostly deprecated).Senior
  27. 27What are 'Web Speech API' (Synthesis and Recognition)?Senior
  28. 28What is the 'Gamepad API'?Senior
  29. 29Explain 'Web Share API'.Senior
  30. 30What is the 'Beacon API'?Senior
  31. 31What is the 'Vibration API'?Senior
  32. 32Explain the 'Permissions API'.Senior
  33. 33What is the 'Web Bluetooth API'?Senior
  34. 34Explain 'Web Cryptography API'.Senior
  35. 35What is the 'History API' in HTML5?Senior
  36. 36What is 'Canvas Hit Detection' and how is it implemented?Senior
  37. 37Explain the 'Passive Event Listeners' in HTML5 performance.Senior
  38. 38What is the 'Window.postMessage()' method used for?Senior
  39. 39Explain 'Integrity' and 'Crossorigin' attributes in <script> and <link> tags.Senior
  40. 40How does 'Feature Detection' differ from 'User Agent Sniffing'?Senior
  41. 41What is the 'Dialog' element in HTML5.2?Senior
  42. 42Explain 'Server-Sent Events' (SSE).Senior
  43. 43What are 'Microdata' and 'Schema.org'?Senior
  44. 44Explain the 'Resource Hints' (dns-prefetch, preconnect, prefetch, preload).Senior
  45. 45How does the 'picture' element handle Art Direction?Senior
  46. 46What is the 'Content Security Policy' (CSP) in HTML meta tags?Senior
  47. 47What is the Intersection Observer API?Senior
  48. 48Explain the difference between <b> vs <strong> and <i> vs <em> in HTML5.Senior
  49. 49Explain the 'srcset' and 'sizes' attributes for responsive images.Senior
  50. 50What is the significance of the <template> tag?Senior
  51. 51How does the 'Shadow DOM' provide encapsulation in HTML5?Senior
  52. 52What are Custom Elements in the context of Web Components?Senior
  53. 53Explain the 'Service Worker' lifecycle and its role in HTML5.Senior
  54. 54What is the HTML5 Cache Manifest (and why is it deprecated)?Senior
  55. 55Explain the concept of WebSockets in HTML5.Senior
  56. 56HTML5 Advanced Interview Question 10Beginner
  57. 57HTML5 Advanced Interview Question 9Senior
  58. 58HTML5 Advanced Interview Question 8Intermediate
  59. 59HTML5 Advanced Interview Question 7Beginner
  60. 60HTML5 Advanced Interview Question 6Senior

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Frequently asked questions

Are these HTML5 interview questions up to date for 2026?

Yes. This page reflects 60 HTML5 interview questions kept current with today's frameworks, tooling and interview trends, with each answer maintained and dated.

What HTML5 topics should I focus on in 2026?

Prioritise the fundamentals plus the modern patterns interviewers ask about now. Each question here includes a detailed answer, code example and common mistakes so you can target the highest-impact areas.

Are these questions free?

You can read the question and a short answer for free. A subscription unlocks the full detailed explanation, real-world example, common mistakes and follow-up questions for each one.