This is our documentation section explaining how to build extensions for the 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 in 2013, 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 supports most Chromium extension APIs, as well as its own Speed Dial API and an experimental Stash API.
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.