Lesson 29 / 30
Validation Tools
Catch markup errors early with the W3C validator and editor checks before you publish.
The W3C validator
validator.w3.org checks a page's HTML against the official spec and flags unclosed tags, invalid nesting, and more.
Lint as you type
Editors like VS Code flag many HTML mistakes live — catching a typo before you even save is faster than validating later.