Tor Browser 13.0

Browse privately, explore freely

Anonymous

Open Source

Privacy

The strongest privacy preserving browser has been updated, including: • Refreshed application icons • New homepage • Bigger new windows These seem minor, but the last one is the most interesting, since several tracking techniques rely on fingerprinting your browser's viewport, and Tor defeats that with some interesting trickery! Letterboxing was introduced in Tor Browser 9.0 2 to allow users to resize their browser window without fear of being fingerprinted by rounding the inner content window (sometimes referred to as the "viewport") down to multiples of 200 x 100 pixels. This technique works by grouping the window sizes of most users into a series of common "buckets", protecting individual users within those buckets from being singled-out based on their window or screen size. In order to preserve these protections when opening new windows, Tor Browser overrides platform defaults and will instead select a size that conforms to our letterboxing steps up to a maximum of 1000 x 1000 pixels. However, while that may have been fine in the past, a max width of 1000px is no longer suitable for the modern web. For example, on many newer websites the first responsive break point lies somewhere in the range of 1000 – 1200px, meaning by default Tor Browser users would receive website menus and layouts intended for tablet and mobile devices. Alternatively, on certain websites, users would receive the desktop version but with the annoyance of a horizontal scroll bar instead. This, naturally, would lead to users of these websites needing to expand each new window manually before it's usable. In response we've bumped up the max size of new windows up to 1400 x 900 pixels and amended the letterboxing steps to match. Thanks to the increase in width, Tor Browser for desktop should no longer trigger responsive break points on larger screens and the vast majority of our desktop users will see a familiar landscape aspect-ratio more in-keeping with modern browsers. This particular size was chosen by crunching the numbers to offer greater real estate for new windows without increasing the number of buckets past the point of their usefulness. As an added bonus, we also expect that Tor Browser users will not feel the need to manually change their window size as frequently as before – thereby keeping more users aligned to the default buckets.