2 browsers to take bite out of cookies

NEW YORK — New protections in Apple’s Safari and Mozilla’s Firefox browsers aim to prevent companies from turning “cookie” data files used to store sign-in details and preferences into broader trackers that take note of what users read, watch and research on other sites.

Lance Cottrell, creator of the privacy service Anonymizer, said Apple’s effort was particularly significant, as it takes aim at a technique developed by tracking companies to override users’ attempts to delete their cookies.

Unlike Firefox, Safari makes these protections au- tomatic in updates coming Tuesday to iPhones and iPads and a week later to Mac computers.

To get the protections, users will have to break the habit of using Google’s Chrome browser, which by some estimates has more than half of the worldwide browser usage. Safari and Firefox have less than 20 percent combined.

Even then, Safari and Firefox can’t entirely stop tracking. For starters, they won’t block tracking within Facebook or Google themselves. Nor can they help much when with phone or tablet apps, unless the app happens to embed Safari, as Twitter’s iPhone app does.

Safari will try to automatically distinguish cookies that are useful from ones that are there just to track people. Apple notes that cookies can appear in unexpected places, such as sites that embed “like” and “share” buttons. Now, those cookies will be blocked until users click on one of those buttons, in which case there will be a prompt for permission to allow the tracking.

Firefox has an anti-tracking feature that also tries to distinguish tracking cookies from useful ones. But it’s on by default only on Apple’s mobile devices. Otherwise, a users needs to turn it on or use a private-browsing mode, which gets more aggressive at killing cookies, including useful ones.