HTML and CSS Reference
Opera Mini is a proxy-based browser that doesn't work like a normal web browser. Usually, you install
a browser on your device that has full rendering capabilities. When a web page is browsed to, the code,
images, and other assets that make up that web page are downloaded to your device and interpreted
and assembled into a web page by the browser for you to interact with. But Opera Mini does not have full
rendering capabilities; it is merely a thin client that can display a static format similar to PDF called OBML
(Opera Binary Markup Language). The web-page code and assets, when requested, are actually downloaded
to a server farm to be assembled into the web page and are then compressed into this OBML format.
The OBML page is then sent to the device to be displayed. This system has some big advantages: First, OBML
is a static, compressed format. The size of the pages you are viewing can be reduced by up to 90 percent
using this system, meaning much smaller downloads, which is great for those on slow networks and those
still paying for web access by the kilobyte. Second, because rendering is done on the server, the Mini client
is very small and simple; therefore, it can run on low-powered phones—pretty much anything with a JVM
(Java Virtual Machine).
Opera Mini does have its disadvantages too. Rendering will not look as nice, because many styling features,
such as box shadows and web fonts, are turned off to save on bandwidth and processing power require-
ments. In addition, OBML just provides a static snapshot of the page you are viewing at the time it was ren-
GIFs) won't work, and background script operations, such as Ajax page updates, won't work either. This
means that web applications that rely on heavy scripting may not perform very well, depending on whether
the developer responsible tested in Opera Mini and used progressive enhancement to still provide a work-
But most websites work well on Opera Mini. The point is not to provide a perfect browsing experience,
but to provide a fast, usable browsing experience that works on nearly any device. It is worth installing
Opera Mini on a high-powered device, such as an iPhone. If you are stuck on a slow, mobile phone network
and desperately need to use the web, Opera Mini can be very useful.