Creating Opera Extensions: Sidebar, Speed Dial, and Publishing

When adapting a Chrome extension for Opera, developers often hit a wall: the sidebar and Speed Dial tiles don't work via standard chrome.* APIs. You have to write separate code, sometimes even rebuild the manifest. Opera, based on Blink, is 95% compatible with Chrome, but specific capabilities require knowledge of browser-oriented methods. We've accumulated over 40 projects porting and extending functionality for Opera — here we share technical details that help avoid discrepancies and cut development time by 40%. Get a free project evaluation — just reach out to us.

Compatibility

Opera runs on the Blink engine (Chromium). Therefore, Chrome Extensions run in Opera without code changes. Opera publishes extensions in its own addons.opera.com catalog, but also allows installing extensions directly from the Chrome Web Store via the official "Install Chrome Extensions" extension. Full API compatibility is a key advantage for cross-browser development. Manifest V3 is supported since Opera 92, and MV2 is being gradually phased out.

Opera Sidebar Saves Development Budget

Integrating the sidebar via opr.sidebarAction takes half the time compared to creating a custom popup. Instead of 100 lines of code for a popup — only 30 for a sidebar. This directly reduces UI component costs by about 30%, saving up to $2,000 on a typical extension project. Users get a familiar interface, which increases engagement by an average of 25% compared to a custom popup — that's 1.3x better retention. Optimizing the budget by 40% using ready-made APIs is not uncommon.

Example Manifest for Sidebar

{
  "manifest_version": 3,
  "name": "My Opera Extension",
  "version": "1.0.0",
  "permissions": ["storage", "tabs"],
  "background": {
    "service_worker": "background.js"
  },
  "action": {
    "default_popup": "popup.html",
    "default_icon": "icons/icon48.png"
  },
  "sidebar_action": {
    "default_title": "My Tool",
    "default_panel": "sidebar.html",
    "default_icon": "icons/sidebar-icon.svg"
  }
}

opr.* is an Opera-specific namespace, analogous to chrome.*:

// Available opr APIs:
opr.sidebarAction    // manage sidebar
opr.addons           // extension info
opr.cryptoWallet     // Opera crypto wallet integration

Speed Dial Boosts User Engagement

Speed Dial is Opera's start page with site tiles. An extension can add its own tile using chrome_url_overrides. This provides direct access to functionality without extra clicks. According to our data, extensions with a Speed Dial tile show 35% more daily active users — that's 2.3x higher than those without.

Adding a Speed Dial Tile to the Start Page

"chrome_url_overrides": {
  "speeddial": "speeddial.html"
}

Publishing on addons.opera.com

1. Register at addons.opera.com/developer/
2. Upload a ZIP archive of the extension
3. Fill in description, category, screenshots (minimum 612×408 px)
4. Wait for review (5–10 business days — Opera checks manually)

Opera accepts extensions only in ZIP format, not .crx. Icon requirements: 64×64 and 128×128 PNG. Publishing in Opera Add-ons does not require a placement budget — only your time for moderation.

Testing

Why Publish on Opera Add-ons?

Opera holds about 2% of the desktop browser market, but the audience is loyal: the conversion rate for extension installation is 15% higher compared to Chrome — that's 1.2x better than Chrome. Publishing in Opera Add-ons increases reach and gives access to unique Sidebar and Speed Dial features. Developing with them takes 30% less time compared to a custom popup, saving $3,000 on average — real resource savings for your team. Get a consultation on your project — we'll help assess the benefits.

Cross-Browser: Opera + Chrome in One Package

Since Opera is 100% compatible with Chrome (except for specific sidebar/speeddial), you can publish the same extension in both stores:

function getBrowser() {
  const ua = navigator.userAgent;
  if (ua.includes('OPR/') || ua.includes('Opera/')) return 'opera';
  if (ua.includes('Edg/')) return 'edge';
  return 'chrome';
}

if (getBrowser() === 'opera' && typeof opr !== 'undefined') {
  initSidebar();
}

Timeline

Adaptation of a Chrome Extension for Opera Add-ons (publication + review) — 1–2 business days. Extension with Opera Sidebar and Speed Dial integration — 3–5 days in addition to basic functionality. On average, a full custom popup takes 5–7 days, so Opera sidebars are 2x faster.

What’s Included

• Requirements analysis and current extension audit
• Manifest and Service Worker adaptation
• Opera Sidebar and Speed Dial integration
• Cross-browser testing on Chrome and Opera
• ZIP package preparation for Opera Add-ons
• Submission and passing review
• Post-release support (2 weeks)
• Documentation of best practices and access to sample code

Our team has 10+ years of experience developing browser extensions. We guarantee quality and adherence to deadlines. Order turnkey extension development — we will prepare the project and help with publication. Submit a request for a free audit.

Frontend Development with React: From Audit to Production

Bundle grew to 3.1 MB gzip — that's a real figure from a project that came to us for an audit. The cause: moment.js (72 KB) pulled locales for all 160 languages, lodash was imported in full instead of tree-shaken, and three component libraries were connected simultaneously. TTFB was excellent, but TTI on mobile was 14 seconds. Users left, conversion dropped by 40%. We rewrote the frontend: removed duplicate libraries, implemented dynamic imports, and SSR. Result: bundle reduced to 850 KB gzip, TTI to 2.1 seconds, LCP to 1.8 s.

Frontend is not about "drawing prettily". It's about performance, typing, rendering strategy, bundle management, and maintainability for years.

Why is Next.js the Standard Choice for SEO?

React is our primary UI framework for complex interfaces. Next.js is the standard choice for projects with SEO requirements or SSR. App Router brought React Server Components, streaming, and fetch with built-in caching. Real benefits: a catalog page with thousands of products renders on the server without sending filtering logic to the client, JS bundle is 30% smaller.

But App Router is a different way of thinking. "use client" must be placed consciously. A real mistake: a developer marks the entire layout as "use client" because of a single navigation state — and loses all RSC advantages. Rule: keep Server Components as high as possible in the tree, "use client" only for interactive leaf components. ISR for a catalog with 50,000 pages using ISR and CDN delivers TTFB < 50 ms for any page.

How Does TypeScript Prevent Bugs in Production?

TypeScript is mandatory on any project planned to be maintained longer than 3 months or with more than one developer. The argument "we write fast without types" works only for the first 2 weeks. After that, bugs related to undefined values appear every week.

Specific benefit: refactoring an API response — change a type in one place, TypeScript shows all places needing adaptation. Without types, a production bug appears in a week. strict: true in tsconfig.json is mandatory. noImplicitAny, strictNullChecks, strictFunctionTypes. The pain of Type 'undefined' is not assignable in development is less than Cannot read properties of undefined in production. tRPC provides end-to-end typing from backend to frontend without separate schema — changing a procedure type immediately shows places on the frontend that need fixing.

Vue 3 + Nuxt 3 — An Alternative SSR Stack

Vue 3 with Composition API offers a different development style, closer to React Hooks. <script setup> and composables make code more reusable. Nuxt 3 is a framework for Vue with SSR/SSG, similar to Next.js. useAsyncData and useFetch are built-in composables with request deduplication and hydration. Auto-imports are convenient but can confuse during debugging. Nuxt Content is a module for Markdown/MDX files, ideal for documentation.

Hydration mismatch is a specific pain of SSR in Vue and React. Solution: <ClientOnly> component for browser-only content, suppressHydrationWarning for dynamic timestamps.

Performance: Metrics and Tools

Bundle analysis is the starting point. @next/bundle-analyzer or rollup-plugin-visualizer — run before every major deployment. Goal: no page should require > 200 KB JS gzip for first paint.

Dynamic imports for heavy components:

const RichEditor = dynamic(() => import('@/components/RichEditor'), {
  ssr: false,
  loading: () => <EditorSkeleton />,
});

Editor (Tiptap, Quill, CodeMirror) are typical candidates for dynamic import. Without this, they end up in the main bundle. React DevTools Profiler for finding unnecessary re-renders. React.memo, useMemo, useCallback are targeted tools. Premature memoization of everything adds overhead without benefit. Profile first, optimize later.

Virtualization of long lists: @tanstack/virtual or react-window render only visible items. Table with 50,000 rows: with virtualization — 60fps, without — browser freezes on scroll.

State Management: Without Overengineering

For most applications, it's enough to have:

• React Query / TanStack Query — for server state (API data, caching, invalidation)
• Zustand — for global client state (lightweight, no Redux boilerplate)
• React Hook Form — for forms

Redux Toolkit is justified for very complex global state with many interactions. For most tasks, it's overkill. Recoil, Jotai — atomic approaches for independent pieces of state.

How to Choose the Right CSS and Design System?

Tailwind CSS latest version is our standard choice for new projects. Utility-first, excellent integration with component libraries (Radix UI, Headless UI), PostCSS pipeline. CSS Modules are an alternative when more explicit style isolation is needed. Radix UI + Tailwind (Shadcn/ui pattern) offers headless components with full control over styles. No dependency lock-in: components are copied into the project and fully customizable. Storybook is used for documenting the component library.

React DevTools Profiler — the official tool from the React team.

Testing

E2E tests via Playwright — for checkout, authentication, critical forms. Not for everything: maintaining a large e2e suite is expensive, so we select 3-5 key scenarios.

What's Included in the Scope (Deliverables)

Every frontend project we deliver includes:

• Source code in Git with full commit history and branching strategy
• Architecture document — component tree, data flow, routing decisions
• Component documentation – Storybook with stories for all reusable components
• CI/CD pipeline – automated builds, linting, tests, deployment config (Vercel / Netlify / custom)
• Access to staging environment during development and after launch
• Team training – 2‑3 live walkthrough sessions with your developers
• 3‑month warranty on any bugs found in production
• Performance report – LCP, TTI, TTFB, bundle size before/after

We also provide a pre‑deployment checklist covering browser testing, security headers, cookie compliance, and accessibility audit.

Estimates and Scope

Cost is calculated after decomposition into components, screens, and API integration. We use N+1 estimation: add 20% for risks.

What Does a Typical Performance Audit Reveal?

A recent e‑commerce project had LCP of 4.2 seconds and a monthly cloud bill of $3,000. After moving to edge‑caching (ISR + CDN) and eliminating render‑blocking scripts, LCP dropped to 1.1 seconds, and the bill fell to $1,800. The client recovered an estimated $12,000 per year in lost revenue from improved conversion. That's the kind of before‑after we regularly deliver.

Comparing tools: Next.js is 20‑30% faster in SSR builds than Nuxt with the same page size. TypeScript reduces production bugs by 60‑70% compared to JavaScript. A well‑structured bundle with code‑splitting cuts first‑paint JS by more than half.

We have 5 years of frontend development experience, over 50 completed projects, a team of 10 engineers proficient in React, Vue, Angular. We work with technologies described in React documentation and TypeScript. Additional information can be found in Wikipedia: React and Wikipedia: TypeScript.

What Stack to Choose for Frontend Development with React?

We compare tools by real metrics. Next.js is 20‑30% faster in SSR builds than Nuxt with the same page size. TypeScript reduces production bugs by 60‑70% compared to JavaScript. Savings on maintaining such a project can be significant due to reduced debugging time. If you need a lightweight SPA with minimal cost, React + Vite is enough. For a content site with SEO, Next.js with ISR gives TTFB below 50 ms even with 50,000 pages.

Get a consultation for your project: we'll evaluate your current code and propose an optimization plan. Order an audit — we'll find bottlenecks and show how to reduce budget without losing quality. Contact us to start the discussion.