Tor Browser includes a “Security Slider” that lets you increase your security by disabling certain web features that can be used to attack your security and anonymity. Increasing Tor Browser’s security level will stop some web pages from functioning properly, so you should weigh your security needs against the degree of usability you require.

Accessing the Security Slider

The Security Slider is located in Torbutton’s “Security Settings” menu.

Security Levels

Increasing the level of the Security Slider will disable or partially disable certain browser features to protect against possible attacks.

Safest
At this level, HTML5 video and audio media become click-to-play via NoScript; all JavaScript performance optimizations are disabled; some mathematical equations may not display properly; some font rendering features are disabled; some types of image are disabled; Javascript is disabled by default on all sites; most video and audio formats are disabled; and some fonts and icons may not display correctly.
Safer
At this level, HTML5 video and audio media become click-to-play via NoScript; all JavaScript performance optimizations are disabled; some mathematical equations may not display properly; some font rendering features are disabled; some types of image are disabled; and JavaScript is disabled by default on all non-HTTPS sites.
Standard
At this level, all browser features are enabled. This is the most usable option.