[clarification needed] It has been the subject of privacy and security controversies and was banned in India on 29 June 2020, shortly after the China–India skirmishes started.

[5] It is known for its small app size and data compression technology, making it popular in emerging markets where people tend to have mobile phones with more limited device memory and internet bandwidth.

[10] UCWeb claims that the cloud system used by the browser tends to fetch data from the closest servers available, making the loading process quicker and smoother for users.

[11] In May 2015, the American National Security Agency (NSA) documents leaked by whistleblower Edward Snowden indicated that UC Browser leaks sensitive data like international mobile subscriber identities, international mobile station equipment identities, MSISDN's, Android ID's, MAC addresses, and geolocation and Wi-Fi-related data without any encryption.

The documents also revealed that the Australian Signals Directorate (ASD) had identified UC Browser as a security weak point.

The Snowden documents revealed that in cooperation with its Five Eyes partners, ASD hacked the UC Browser and infected smartphones with spyware.

[19] In May 2016, Alibaba Group provided Citizen Lab with updated versions of UC Browser in order to verify their security fixes to these issues.

The subsequent update published by Citizen Lab indicated that not all of the previously identified data leaks and privacy breaches had been fixed in UC Browser.

[20][21] In 2017, the Centre for Development of Advanced Computing (C-DAC), a scientific research unit within India's Ministry of Electronics and Information Technology (MEITY), began a technical investigation into the "several major privacy and security vulnerabilities that would seriously expose users of UC Browser to surveillance and other privacy violations" alleged in the report.

In October 2012, UC Browser topped Opera in Google Play's free Android app download category in India for the first time.

[36] In May 2020 India's National Security Council recommended that UC Browser and other Chinese-owned apps be blocked due to cyber-security concerns following the 2020 China–India skirmishes .

[39] In August 2013, UC Browser provided distribution channels of companies like AppURL Initiative[40] and partnered with distributor Gameloft to sell its products.

[41] In 2013 also it announced a partnership with Trend Micro, under which both companies worked to provide mobile web safety assessments in the browser.

[42] On 26 June 2020, the Government of India banned UC Browser, along with 58 other Chinese apps such as TikTok and WeChat, citing data and privacy issues and claiming that it is a "threat to the sovereignty and integrity" of the country.