A Chrome Extension to uncover the semantics of the web.

The Meaningless extension looks at the elements and attributes that make up the web pages you browse, even the dynamic content that's loaded after a page is initially served, and figures out how "semantic" the resulting page is. That is to say, if the web developer wanted to put a dialog in the web page (for which there is no straightforward HTML element), what lengths did they go to to convey to you, to search engines, and to assistive technology that the UI you're viewing isn't just a collection of boxes, but is instead a "dialog"?

Every HTML element has some meaning, even if it's to denote that a block of content doesn't have a well-understood pre-defined meaning (e.g. div and span).

As the web has evolved, side-contracts have become a common way for developers, search engines, and assistive technologies (like screen readers) to produce and consume information about types of content for which HTML doesn't yet include nouns. The most prominent of these are WAI-ARIA, Microformats, and Schema.org.

Many other sorts of side-contracts exist along side these, notably "progressive enhancement" through JavaScript frameworks like Dojo, Sencha, and JQuery UI. Meaningless doesn't detect these frameworks directly, instead relying on their support for ARIA to detect their overall meaning. The theory here is that any framework worth it's salt must be accessible, and if it's not...well is that content really semantic? We think not.

About once a day, the Meaningless extension checks in with the Meanginless reporting service and uploads anonymous, aggregate statistics about the total number of elements seen, their classificiations, and detailed breakdowns of the most common types of semantics. None of this is traceable to an individual, and no personally identifiable information is collected or logged (insofar as AppEngine enables disabling of logging). No information beyond semantic composition of individual elements on pages is reported about the sites you visit. No URLs are logged and no session is ever leaked. If you want to verify all of this for yourself, you're in the right place: the extension and reporting system are all Open Source and via this repository.

No.

The extension has been carefully architected not to impact page loading or affect overall browsing performance. Yes, it must do some work to charachterize the elements on pages, but it uses several techniques to ensure good performance, even for the tab-collecting among us:

• The extension does the minimum necessary. No bloated libraries or boilerplate code; the code is tuned to do the minimum needed to charachterize the semantic content of a page.
• Meaningless only runs when the browser isn't doing more important work for you. Thanks to Mutation Observers it can follow along as pages change over time without impacting the performance of other scripts on the page.
• Storage of aggregate statistics and uploading to the reporting service is off-loaded to a background task, keepings your tabs responsive.
• Communication between your tabs and the background process is throttled and messages are batched to ensure that your browsing remains responsive.

As with any code that is run on each page, there is some cost, but thanks to defensive coding, Meaningless shouldn't ever slow down your browsing. If you have concerns about the extension or reporting service, please file an issue here.