Graphcheckr helps you check whether the current web page has the metadata needed for clear search results and rich link previews. Instead of opening page source or manually searching through the document head, Graphcheckr gives you a focused one-click audit of the active page. It highlights missing, broken, or incomplete tags and presents the results in a readable interface. Graphcheckr checks common page metadata, including Open Graph tags, card metadata, title, description, canonical URL, viewport, charset, robots directives, favicons, theme color, structured data, sitemap references, and app-related metadata. The extension is built for developers, site owners, content teams, and testers who want a fast way to catch metadata issues before publishing or sharing a page. Key features:

Inspect Open Graph metadata
Review title, description, canonical URL, viewport, charset, and robots tags
Detect missing or incomplete metadata
Preview detected sharing images
Find favicons, app icons, theme color, and app metadata
Detect structured data when available
Discover sitemap references when available
View checks grouped by clear categories
See pass, warning, fail, or info status for each check
Get a weighted score and overall result
Switch between light, dark, and system themes
Supports English and Swedish

Graphcheckr only audits the page you are currently viewing when you interact with the extension. It does not request broad host permissions and is designed for the single purpose of helping you verify page metadata. Source code: https://github.com/ShadowNineX/Graphcheckr

ShadowNine

Published Firefox add-on:

Graphcheckr