MassBrowser is a free to use and open source tool designed to circumvent Internet censorship.

Furthering the development of MassBrowser, a volunteer-driven censorship circumvention tool, it has been designed and developed by the Secure, Private Internet (SPIN) Research Group at the University of Massachusetts Amherst. MassBrowser operates with the help of internet users in uncensored locations who volunteer to help users in censored locations.

Instead of relying solely on publicly hosted proxy servers, MassBrowser utilizes volunteers. Volunteers are users residing outside the censored regions who are willing to help censored users gain open access to the Internet by allowing them to proxy their traffic through their devices. These volunteers may have changing and non/public IP addresses, making it more difficult for censors to block them using traditional methods. These volunteer proxies are given full control over what they feel comfortable proxying.

This project supports the development of a final release desktop version of MassBrowser as well as an Android version, setting up and deploying a performance measurement framework, usability improvements, and ultimate adoption by third party systems.