Free Modern Web Standards Checker

Modern Web Standards Checker

Audit your website for modern web standards and get actionable fixes to improve quality and reliability.

Free Best Practices Checker

Does your site follow modern web standards?

Check HTTPS, doctype, charset, viewport, PWA manifest, compression, and more. Get an instant best-practices score with actionable recommendations. No login required.

What we check

HTTPS Usage

Verify all resources are loaded over HTTPS

Console Errors

Detect JavaScript errors and warnings in the console

Deprecated APIs

Check for use of deprecated web platform features

Image Aspect Ratio

Verify images have correct width/height attributes

Source Maps

Check if source maps are exposed in production

Browser Errors

Identify cross-browser compatibility issues

Doctype Declaration

Verify proper HTML5 doctype declaration

Charset Declaration

Check character encoding is properly defined

Related tool

From standards to rankings

Modern web standards are the foundation. To see how they affect your search performance, run an SEO and a performance check next.

Try SEO Checker

Or Check performance

SiteRepair

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