MarkupLint

by molawawasaxa@gmail.com · Tools

Manifest V3 Free

View in Chrome Web Store Data as of 16 Oct 2026

Instant HTML validation for web developers. Check markup quality offline by AIO.com.ai

Users

−2 in 30 days

Rating

0.0 / 5

unchanged in 30 days

Ratings

0 in 30 days

Store rank

#364K

#276K among extensions

Version

1.0.0

updated 29 Oct 2025

Users

monthly, 12 months

Latest, 16 Oct 2026: 2 usersMove the mouse over the chart for any month

Ratings count

monthly, 12 months

Latest, 16 Oct 2026: 0 ratingsMove the mouse over the chart for any month

The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.

About MarkupLint

MarkupLint is a powerful HTML validation extension for web developers and designers. Instantly analyze any webpage's HTML structure, accessibility, and semantic markup quality without leaving your browser. Press Alt+Shift+V or click the toolbar icon to validate the current page. Results appear in the browser console with color-coded issues, warnings, and suggestions. Features include DOCTYPE validation, heading hierarchy checks, accessibility audits, duplicate ID detection, and semantic HTML5 verification. Works 100% offline with no external requests. Perfect for debugging, learning web standards, and ensuring clean, valid HTML markup. Developed by AIO.com.aiRetry