UC Browser is a web browser developed by mobile internet company UCWeb, a subsidiary of the Alibaba Group. It was the most popular mobile browser in India and Indonesia, and the second most popular one in China as of 2017. Its world-wide browser share as of May 2022 is 0.86% overall (and 1.48% on smartphones) according to StatCounter.
Originally launched in April 2004 as a Java-only application, it was subsequently made available on a number of platforms including Android, iOS, BlackBerry OS, Java ME, Symbian, Windows Phone, and Microsoft Windows. As of 2020, Android is the only OS still supported by the browser.
It has been the subject of several security and privacy controversies, and was banned in India on June 29, 2020, shortly after the 2020–2022 China–India skirmishes started.
Functionality
UC Browser is a cross-platform web browser primarily targeted at mobile phones. 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. In particular, the browser is unique in its use of proxy servers, which run data through UCWeb servers before sending it to the user's device, enabling data compression but also posing privacy risks. Additional features of the browser include cloud acceleration, multi-file format downloading, HTML5 web app and cloud syncing features, and "fast download", a feature that downloads files in multiple parts simultaneously.
Platforms
UC Browser is available as both an Android app and an iOS app, and is also available on several other older or discontinued mobile operating systems including BlackBerry OS, Symbian, and Windows Phone. While primarily a mobile app, UCWeb also offers a Microsoft Windows desktop version (there is no macOS version).
Data compression
UC Browser uses proxy servers to compress web pages before sending them to users. This process requires less memory on the user's device and lowers data costs; however, it also poses privacy and security risks as all of the data accessed by the user through UC Browser first runs through a UCWeb server, rather than going directly to the user's device.
UC+: HTML5, WebApp and add-ons
In July 2013, UCWeb announced the UC+ Open Platform. The platform consists of a WebApp store, an add-on platform and an Application Bookmark Platform. It went live with the launch of UC Browser v9.2 for Android.
Developers can use a provided SDK to create programs that the browser runs in different scenarios. Users can download and install them from the browser's add-on panel. Examples include sharing to social media, webpage translation, augmented reality, and voice control. The Application Bookmark Platform allows partner websites to put up a QR code on UC Browser for users to scan, which adds the webpage to their bookmarks. This platform was among the first in China.
Download management
The browser supports simultaneous downloads and includes a download manager, including pages for offline reading. It supports pausing and resuming downloads. The current version of the download manager has features designed to solve common problems while downloading, such as an intermittent internet connection and mislabeled files. The download process can continue after the app is closed, and can also automatically resume if the download is interrupted. The download manager sorts downloaded files by type and places them in respective folders.
Cloud system
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.
Privacy and security vulnerabilities
In May 2015, 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. These leaks were used by intelligence agencies to track users. The documents also revealed that the Australian Signals Directorate (ASD) had identified UC Browser as a security weak point. Its widespread use in China, India and Indonesia made it particularly attractive to ASD. The documents revealed that in cooperation with its Five Eyes partners, ASD hacked the UC Browser and infected smartphones with spyware. The ASD declined to comment in relation to the revelations.