Engineering service
Opera Browser Development
We build Opera add-ons, test Chrome extensions against Opera, or build Opera-style sidebar and workspace features into your own Chromium-based browser, since Opera's own code cannot be forked.
- 15+ years of experience
- 300+ projects delivered
- Clients worldwide
- NDA available
Overview
What this is, and when it is the right call
Opera is a Chromium-based browser, but Opera's own code is proprietary, so it cannot be forked the way Chromium can. What we can build falls into three routes: an add-on for Opera users, a Chrome extension tested on Opera, or your own Chromium-based browser with Opera-style features such as a sidebar, built-in tools and workspaces.
Which one do you need? If you want to reach people who already use Opera, choose an add-on or extension. If you want your own product with that kind of interface, choose the browser. Tell us the goal and we will point you to the smaller route that meets it.
Who this is for
- Teams that want to reach Opera users with an add-on or extension.
- Extension developers who need to confirm their Chrome extension works in Opera.
- Companies that like Opera-style features such as a sidebar or built-in tools and want them in their own browser.
- Anyone asking whether Opera itself can be modified or forked.
How it works
Architecture at a glance
Route 3: Opera-style features in your own browser
Opera-style features in your browser
Sidebar, built-in tools, workspaces and a layout designed for your product.
Feature modules
Each feature built as a separate module with a small footprint in Chromium code.
Chromium
Blink, V8, Content, networking and the sandbox, kept as close to upstream as possible.
Build and release
- Windows
- macOS
- Linux
Build system, CI, installers, code signing and updates.
- Your productWhat your users see
- Our engineeringModifications and protections
- UpstreamKept as close to unmodified as possible
- Platforms and releaseBuild, sign and deliver
What we offer
What we engineer: Opera Browser Development
Opera Add-ons Catalog Packaging
We package and submit browser add-ons through Opera's own add-ons catalog rather than modifying Opera's source, which is proprietary.
Cross-Browser Extension Compatibility Testing
We test an existing Chrome Web Store extension against Opera's Chromium-based extension support and fix the behavior differences we find.
Sidebar and Panel Modules for a Custom Browser
When you want your own browser rather than an Opera add-on, we build sidebar and panel UI as Chromium-based modules you own outright.
Workspace and Tab-Group UI
We implement workspace-style tab organization inside your own Chromium-based browser, modeled on the interaction pattern rather than on Opera's proprietary code.
Built-in VPN or Ad-Block Alternatives
For a custom browser, we integrate a third-party VPN SDK or build our own ad-blocking layer, since Opera's own VPN and ad blocker are not code we can reuse.
Gaming-Oriented Browser Features
For a custom browser aimed at gamers, we build resource-limiter panels and performance overlays inspired by Opera GX's feature set, implemented independently on Chromium.
Deliverables
What you get
- 01
Route recommendation
A short written answer on which of the three routes fits your goal, and why the others do not.
- 02
Opera add-on or extension
A packaged extension prepared for Opera's add-ons catalog, if you choose the first route.
- 03
Opera compatibility pass
Testing of an existing Chrome extension on Opera, with fixes for Opera-specific behavior.
- 04
Custom browser with feature modules
A Chromium-based browser with the Opera-style features you select, if you choose the third route.
- 05
Submission support
Help preparing listings and responding to review feedback for the add-ons store.
- 06
Test notes
A record of what was tested and which Opera versions and platforms it covers.
Compare
Which route fits
The routes differ mostly in how much you own and how much you must maintain.
| Route | Result | Effort | Choose it when |
|---|---|---|---|
| Add-on for Opera | A feature installed by Opera users from Opera's add-ons catalog | Low | You want to reach existing Opera users with a specific feature. |
| Chrome extension tested on Opera | One extension that works across Chrome, Opera and other Chromium browsers | Low to medium | You already have or plan a Chrome extension and want Opera users covered. |
| Your own Chromium-based browser with Opera-style features | A separately branded browser you control | High | You want a browser product with a sidebar, built-in tools or workspaces that you own. |
Why it matters
What this gives you
An Honest Read on What's Possible
We tell you upfront that Opera's code is proprietary and cannot be forked, so you choose between an add-on and your own browser with full information instead of finding the limit mid-project.
One Extension Codebase Covers Several Browsers
A Chrome Web Store extension built and tested against Opera generally keeps working in Chrome, Edge and other Chromium-based browsers with the same code.
No Wasted Effort on Code You Cannot Change
Because we start by confirming which route your goal actually needs, you do not pay for engineering time spent probing code that is off-limits.
A Real Browser When You Need Full Control
If an add-on cannot reach what you need, the alternative is a Chromium-based browser you own outright, not a dead end.
Our approach
How an Opera-related project runs
Pick the route
We clarify your goal and choose between add-on, tested extension or your own browser.
You get: A route recommendation
Design
We define the features, the interfaces they use and which Opera behaviors matter for your users.
You get: A feature and compatibility plan
Build
We build the add-on, the extension changes or the browser feature modules.
You get: A working build for your target platforms
Test on Opera
We test in Opera and against its add-ons store requirements, or across your browser's platforms for route 3.
You get: Test results and fixes
Release
We prepare store submissions or signed installers, and document how to keep it updated.
You get: Listing or release pipeline
When this is not the right fit
A few cases where this approach may not be the best choice for you.
- You want to modify Opera itself. Its code is proprietary, so we cannot patch it. Use an add-on or your own browser.
- Your feature only needs to run in the browser users already have. A Chrome extension is cheaper and works in Opera too.
Tech stack
Technologies we use
The engines, APIs and tools behind our opera browser development work.
ChromiumChrome Web Store APIsOpera Add-ons CatalogManifest V3
C++
JavaScriptFAQ
Questions engineers ask before starting
No. Opera's own code is proprietary, so it cannot be forked or patched. You can reach Opera users with add-ons, or build your own Chromium-based browser that offers similar features.
Our services
Related services
Explore more services that work alongside this one.
Talk to a Browser Engineer
Talk to Chromium Engineers About Opera
Tell us what you need on Opera. We will say honestly what is possible and what a Chromium-based alternative would take.
