Practical guide

HTML, CSS, and JavaScript: How a Basic Website Fits Together

A simple website can start with three separate responsibilities: HTML describes the content, CSS styles it, and JavaScript responds to user actions. Keep the first version small and test each part in a browser.

What to do

  1. Create an HTML document with a doctype, a language attribute, a character encoding, a viewport meta tag, and meaningful headings and links.
  2. Link a separate CSS file to control layout, typography, and mobile breakpoints. Prefer flexible widths and readable contrast over fixed desktop-only dimensions.
  3. Add JavaScript only for behavior that needs it, such as validating a small form or filtering a list. Keep data and display logic understandable.
  4. Open the page locally and test keyboard navigation, mobile width, missing assets, and the browser console before publishing.

Checks and limitations

  • Do not put passwords, API secrets, or private configuration in client-side HTML or JavaScript; visitors can inspect downloaded files.
  • A page that looks correct in one desktop browser still needs testing at narrow widths and with keyboard navigation.