<span class="application">[Tor Browser](https://www.torproject.org)</span> is a web browser based on [Mozilla Firefox](https://www.mozilla.org/firefox/) but configured to protect your privacy.
Security vulnerabilities in JavaScript have been used to [deanonymize Tor Browser in the past](https://arstechnica.com/information-technology/2013/08/attackers-wield-firefox-exploit-to-uncloak-anonymous-tor-users/).
You can change the security level of <span class="application">Tor Browser</span> to disable browser features as a trade-off between security and usability. For example, you can set the security level to *Safest* to disable JavaScript completely.