HTML Best Practices
Writing valid, clean, accessible HTML is a professional skill. These are the rules that distinguish beginner code from production-ready code that employers and users trust.
The 10 Essential Rules
Example 1 — Production-Ready HTML
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"/> <!-- 1. Always first --> <meta name="viewport" content="width=device-width,initial-scale=1"/> <title>Unique, Descriptive Title</title> <!-- 2. Never empty --> <link rel="stylesheet" href="style.css"/> <!-- 3. CSS in head --> </head> <body> <header>...</header> <!-- 4. Semantic tags --> <main> <h1>One h1 per page</h1> <!-- 5. ONE h1 --> <img src="photo.webp" <!-- 6. WebP format --> alt="Descriptive alt text" <!-- 7. Always alt --> width="800" height="400" <!-- 8. Set dimensions --> loading="lazy" <!-- 9. Lazy load --> /> </main> <footer>...</footer> <script src="app.js"></script> <!-- 10. JS at end of body --> </body> </html>
These 10 rules cover 90% of what separates a good HTML developer from a beginner. Follow all of them every time.
10 Best Practice Rules
1. DOCTYPE + charsetAlways. On every single file. No exceptions.
2. Non-empty titleUnique, descriptive, 50-60 chars. Shows in tabs and Google.
3. CSS in headNever inline styles for layout. CSS belongs in a file or style tag in head.
4. Semantic HTMLUse header, nav, main, article, section, aside, footer. Avoid div soup.
5. One h1 per pageThe main topic. Google and screen readers treat it specially.
6. WebP images30% smaller than JPEG. Use for all new photos.
7. alt on every imgDescribe what is in the image. Blank alt="" for decorative images.
8. Image dimensionswidth and height prevent layout shift (CLS). Required for Core Web Vitals.
9. loading=lazyOn all images and iframes below the fold. Speeds up initial load.
10. JS at end of bodyScripts block HTML parsing. Place before