What is an HTML Validator?
An HTML validator checks HTML markup for common structural, accessibility-related, and compatibility problems. Validation helps developers find mistakes before publishing a webpage and makes HTML easier to maintain.
How to Validate HTML Online
- Paste your HTML code into the validator above.
- Click Validate HTML.
- Review the detected issues and warnings.
- Correct the HTML and validate it again.
What ToolSwift HTML Validator Checks
- Unclosed or incorrectly nested common HTML tags.
- Duplicate
idattributes. - Images without an
altattribute. - Missing document language information.
- Basic HTML document structure issues.
- Common deprecated HTML elements.
Why Validate HTML?
Clean HTML is easier to debug, maintain, and update. Checking markup is useful after editing templates, converting designs, or copying HTML from another source. It can also help identify accessibility and structural issues before a page goes live.
HTML Validation vs HTML Formatting
An HTML validator looks for possible markup problems, while an HTML formatter changes the presentation of code by adding indentation and line breaks. Use the HTML Formatter when your goal is to make HTML easier to read.
Frequently Asked Questions
Is this HTML Validator free?
Yes. ToolSwift's HTML Validator is available online at no cost.
Does the validator automatically fix HTML?
No. It reports detected issues so you can review and correct the source yourself.
Can I validate a complete HTML document?
Yes. You can paste a complete HTML document containing elements such
as html, head, and body.
Is HTML validation the same as browser rendering?
No. Browsers can recover from many HTML mistakes. This tool performs local checks intended to highlight common potential problems in HTML markup; it is not a replacement for every standards-compliance test.
