Opera Mini is a mobile web browser developed by Opera Software AS. It was primarily designed for the Java ME platform, as a low-end sibling for Opera Mobile. It was previously developed for iOS, Windows 10 Mobile, Windows Phone 8.1, BlackBerry, Symbian, and Bada. However, it is now developed exclusively for Android.

Opera Mini claims to be all about speed and comfort, saving a user up to 90% of their data and browsing faster, even on slow networks and without disrupting their browsing experience. This is achieved through Opera Mini's Smart Browsing feature which automatically selects the browsing mode for the optimal experience. Opera Mini requests web pages through Opera Software's compression proxy server; this compression server processes and compresses requested web pages before sending them to the mobile phone. The compression ratio is 90% and the transfer speed is increased by two to three times as a result. The pre-processing increases compatibility with web pages not designed for mobile phones. However, interactive sites which depend upon the device processing JavaScript do not work properly.

Additionally, by signing into an Opera Account, Saved Bookmarks, Speed Dials, Opened Tabs can be synchronised between different phones or with the Opera browser on computers, using the "Opera Sync" service.