Documentation for Opera 11 & 12 extensions

With Opera switching from Presto to Chromium and a complete UI remake, our extensions infrastructure has also gotten a major overhaul: from Opera 15 onward, Opera 11 & 12’s extension format is no longer supported, and instead, we’ve switched to Chromium’s extension model. Check out our new documentation for developing extensions for Opera 15 and higher and start building your own extensions.

Getting started

API reference

You can build Opera extensions using the Opera Extensions APIs and open web standards like JavaScript and HTML. This makes Opera extensions easy to create, quick to debug, and fast to install.

Basics and UI elements:

Browser functions:

Finishing up:

Extension tutorials

Templates and code samples

UI guidelines and distribution