Meta data is not just the usual HTML meta tags, but the XFN tags, various microformats, the recently introduced canonical attribute, the no-follow links and so on.
This extension is mainly aimed at web developers that need to verify the description tag of their site to follow the Webmasters' Google Guidelines, but even to who is curious about page contents that are usually not visible, but can reveal interesting site properties.
Alerts are showed when the meta data is not within certain ranges, for example when the description tag is too short, or too long.
There are links to info-sites ( mainly SEO-oriented ) pointing to the exact page about the site you are watching. Feel free to request new links, I'll add only the good ones (there are many sites all showing the same data).
Anyway, in one of the next updates, the links list will be customizable.
download at Chrome Web Store
1.0 - First release
1.1 - Added "visited links" highlighter, better LINK and XFN support.
1.2 - Improved visited link style, improved inspector layout, added iframes count, fixed a bug with Google Reader (and maybe other ajax driven sites)
1.3 - XFN parsing fixes, inspector styles fix, added "commontags" parsing, custom colors via options page.
1.3.1 - improved a[rel] handling, hidden link[archives], fixed refresh bug on unsleected tabs.
1.4 - Fixed nofollow links with only images - introduced warnings - parsed head title - improved microformats - added A REV detection.
1.5 - New icons, links to various webtools.
1.5.1 - Fixed a small bug with the webtools, and added two new sites.
1.6 - Quick link to the options page, "script" tag parsing (to detect analytics, libraries, etc. - hover item for full paths)
1.7 - Added a printable details page, accessible from the popup options
1.7.4 - Cleaned script tags, details page has more data, password safety warning, fixed font styles, meta links are clickable, linked images are showed, speed improvements.
1.7.5 - Fixed some tool links, edited some icons, added "content-language"
1.7.6 - Graphic enhancements
1.7.7 - Basic RDFa implementation.
1.7.8 - Added the requested close button, and "Rich Snippets Testing Tool","Copyscape Plagiarism Checker","Keyword Density Analyzer" tool links
1.7.10 - Fixed graphics issues, visible in latest Chrome Dev
1.8 - Added more unique prefixes to css classes, "always white text" fixed, custom font size, explained "description too long/short" values, removed "show visited links" it is not working anymore due to security issues, fixed head title (added warning and length count), improvements to the printable "page details", checked various sites for layout issues
1.8.1 - G+ profiles extractor.
1.8.2 - Added favicons to external scripts URLs, added links to tags explanations. Bugfixes.
1.8.3 - Style fixes, speed improvements, basic HTML5 report.
Various uncommon META tags
JS test page