HTML Foundations

HTML Validation

Learn to find structural and nesting errors and ship more reliable markup in this beginner-friendly website development lesson.

Learning outcomes

Work on a practice copy, keep filenames lowercase and hyphenated, and create a backup before changing a live website.

Open the relevant project page, file or WordPress screen and confirm you are working on a safe practice copy.
Validate a practice document and fix reported errors.
Inspect the result using browser tools or WordPress Preview; do not publish yet.
Check keyboard use, mobile layout, content accuracy, links, images and privacy where applicable.
Confirm that you can ship more reliable markup, then save a clearly named version or backup.

Ian's practical tip: Preview first, test at desktop and mobile sizes, and keep a recoverable copy before publishing.

Validate a practice document and fix reported errors. The expected result is to ship more reliable markup.

I worked on the intended practice copy. I completed and previewed the activity. I checked mobile layout, accessibility, links and the saved result.