From a privacy perspective Microsoft Edge and Yandex are qualitatively different from the other browsers studied. Both send persistent identifiers that can be used to link requests (and associated IP address/location) to backend servers. Edge also sends the unique hardware identifier of the device to Microsoft, and Yandex similarly transmits a hashed hardware identifier to backend servers. As far as we can tell, this behavior cannot be disabled by users. In addition to the search autocomplete functionality that shares details of web pages visited, both transmit web page information to servers that appear unrelated to search autocomplete.
Doug Leith at Trinity College Dublin
The rankings were revealed in a research paper published by Trinity College Dublin computer scientist Doug Leith. He analyzed and rated the privacy provided by Google Chrome, Mozilla Firefox, Apple Safari, Brave, Edge, and Yandex. Specifically, the study examined the browsers’ sending of data—including unique identifiers and details related to typed URLs—that could be used to track users over time. The findings put the browsers into three categories with Brave getting the highest ranking, Chrome, Firefox, and Safari receiving a medium ranking, and Edge and Yandex lagging behind the rest.
The Best and Worst Browsers for Privacy, Ranked by Dan Goodin at Ars Technica