This is our new documentation section explaining how to build extensions for the new Chromium-based Opera browser for computers. Note: as a developer, you can also grab an Opera Developer build, which has the latest new stuff.
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. At this point, Opera 15 and later versions support most Chromium extension APIs, as well as our own Speed Dial and Stash APIs.
If you have created a Chromium extension before, be sure to try it out in Opera, and if it works fine, upload it to our extensions catalog.
If you're new to Chromium extension development, we’ve prepared a number of tutorials and have included relevant API documentation as well. There is also a step-by-step guide explaining how to use the conversion tool that we’ve built into the extensions catalog.
And if you have questions, contact us.