You may be perfectly happy with the standard Android browser, and there’s certainly no reason not to be as its one of the finest mobile browsers around. However, when you’re on the move and your phone isn’t picking up a 3G signal, web pages tend to load agonisingly slowly.
Opera Mini is a much better choice when bandwidth is limited because it uses gateway servers that compress pages before sending them to your phone. The result is lightning fast performance even when your phone is struggling to maintain a decent connection speed. This alone makes it worth the download as in these circumstances it acts as an excellent companion browser to the standard Android one.
Early versions of Opera Mini on Android were a little bit squiffy but with version 5, things have improved a lot. If you find you really love Opera you can also use OperaBridge to make it your default browser. However, as Opera Mini uses intermediary servers it’s probably best not to use it for really sensitive stuff like online banking.
Opera Mini’s clever use of compression makes it a great option when your phone is struggling to get a decent data connection.