HTML Validator
Check your HTML for errors, warnings, deprecated tags, missing alt attributes, and duplicate IDs.
100% Private
Processed locally
Free & unlimited
Validate HTML
No HTML to validate
Paste your HTML code above and click Validate
Validation Statistics
Tags
0
Errors
0
Warnings
0
Valid
0
Elements
0
Processing Time
0 ms
Unique IDs
0
Duplicate IDs
0
Images
0
Forms
0
Tables
0
Accessibility
0
Depth
-
Max Nesting
-
Comments
0
Scripts
0
Styles
0
Meta
0
Links
0
Buttons
0
Inputs
0
Lists
0
Headers
0
SVG
0
Custom Els
0
Data Attrs
0
A11y Issues
0
SEO Issues
0
Syntax Issues
0
Structure Issues
0
Deprecated Els
0
Deprecated Attrs
0
ARIA Issues
0
Broken Refs
0
Dup Meta Tags
0
Missing Meta
0
Compare with Previous
History
What this tool does not do
- Not a full W3C validator — does not check CSS or JavaScript.
- Does not check CSS or JavaScript validity.
- Limited to structural HTML validation only.
How It Works
1
Paste your HTML
Enter or paste your HTML code into the input area.
2
Click Validate
Click the Validate button to check your HTML structure.
3
Review errors and warnings
See a detailed report of issues found in your HTML.
Frequently Asked Questions
What does HTML validation check?
Unclosed tags, deprecated tags, missing alt attributes, duplicate IDs, and common structural issues in your HTML.
Is this a replacement for W3C validator?
No, it's a quick client-side check. For full standards compliance, use the official W3C validation service.
Is my data uploaded?
No. All processing happens entirely in your browser. Your data never leaves your device.