Here is how Mozilla’s Suggested Tiles feature works

By now you have probably heard about Suggested Tiles, a new feature coming to the Firefox browser's New Tab page in the near future.

Suggested Tiles are already available in pre-release versions of Firefox and we were among the first to publish an article about it here on this site.

It was not clear back then how Suggested Tiles work. While we knew that the user's browsing history played an important part in the selection process, it was not really clear how or where this was done.

For instance, it was unclear which data is submitted to whom in the process and how it would affect user privacy.

Mozilla has created an infographic that highlights "how user data is protected on Firefox New Tab". It outlines how suggested tiles are created and displayed in the browser, and which data is accessible by third-parties.

The process works in the following way

1. Partners submit tile campaign assets to Mozilla (e.g. article links or a homepage url).
2. These assets are reviewed by Mozilla to make sure they comply with rules and style guides. If they do, they are added to the tiles authoring and campaign management server Splice.
3. Splice hands over the data to another server called Onyx which handles tile delivery to Firefox users.
4. Firefox downloads all available tiles based on country and language. This is done without cookies or user tracking, and the decision what is shown on the New Tab Page is made locally by the browser.
5. When a user interacts with a tile, e.g. when it is clicked on, pinned or blocked, it is measured and processed.
6. Onyx submits the interaction data that was collected to Disco, a database used for storage and analysis.
7. Disco aggregates all interactions, anonymizes them before it sends the processed data to the Redshift server.
8. Zenko, a content services reporting tool, is used to create charts and reports from Redshift data which is used by Mozilla for analysis.
9. Mozilla sends reports to partners after campaigns end. The report contains no personally identifiable information, only country and interaction information.

A direct connection between a Firefox user and a tile provider is only established when clicks are made on suggested tiles on Firefox's New Tab Page.

The privacy and identity of Firefox users is protected by the process. Users who don't want to see Suggested Tiles on the browser's New Tab Page can disable the feature easily on the page with a click on the cogwheel icon and the unchecking of "include suggested tiles". Other options include pinning a set of sites to the New Tab Page so that it is filled with your own set of sites or switching to a blank page instead.