Web Push Notifications: Notifications API & Service Worker Integration

A user leaves the site — we lose them. Push notifications (using the Notifications API and Push API) bring back up to 30% of visitors, but implementing has pitfalls: browser blocking, Service Worker errors, incompatibility with some devices. We have implemented notifications for 15+ projects over 5+ years and know how to do it without pain. On one large e-commerce site, integrating push notifications with a custom Service Worker increased return rate by 28% in the first month. At the same time, we avoided typical mistakes: requesting permission after a click, correct handling of notificationclick, and a fallback for iOS.

Why Notifications API Needs a Service Worker?

The Notifications API and Push API are distinct. The former shows a notification through the browser, the latter delivers an event from the server. For notifications when the tab is closed, you need both. A Service Worker is mandatory: it runs in the background and intercepts push events. Without it, notifications only appear when the page is open. The Notifications API allows web pages to display system notifications (MDN). Over 95% of browsers support the API, but for push notifications you also need the Push API. Our React hook for Notifications API and Push API reduces code by half compared to manual implementation.

How to Request Permission and Not Get Blocked?

The main rule is to request permission only after an explicit user action, otherwise the browser will automatically block the request:

async function requestNotificationPermission(): Promise<NotificationPermission> {
  if (!('Notification' in window)) {
    throw new Error('Notifications API not supported')
  }

  if (Notification.permission === 'granted') return 'granted'
  if (Notification.permission === 'denied') return 'denied'

  // Call only from event handler (click, submit, etc.)
  return Notification.requestPermission()
}

Displaying a Notification: On the Page and via Service Worker

For displaying a notification on an open page, use new Notification():

interface NotificationOptions {
  title: string
  body?: string
  icon?: string
  badge?: string
  tag?: string          // Grouping — new notification replaces old one with same tag
  requireInteraction?: boolean // Do not auto-close
  data?: unknown
  actions?: NotificationAction[]  // Buttons in notification (Service Worker only)
}

function showNotification(options: NotificationOptions): Notification | null {
  if (Notification.permission !== 'granted') return null

  const { title, ...rest } = options
  const notification = new Notification(title, rest)

  notification.onclick = (event) => {
    event.preventDefault()
    window.focus()
    notification.close()
    // Navigate based on notification.data
  }

  return notification
}

For notifications when the tab is closed — only through Service Worker:

// service-worker.ts
self.addEventListener('push', (event: PushEvent) => {
  const data = event.data?.json() ?? {}

  event.waitUntil(
    self.registration.showNotification(data.title ?? 'New notification', {
      body: data.body,
      icon: '/icons/notification-icon-192.png',
      badge: '/icons/badge-72.png',
      tag: data.tag ?? 'default',
      data: { url: data.url },
      actions: [
        { action: 'open', title: 'Open' },
        { action: 'dismiss', title: 'Close' },
      ],
    })
  )
})

self.addEventListener('notificationclick', (event: NotificationEvent) => {
  event.notification.close()

  if (event.action === 'dismiss') return

  const url = event.notification.data?.url ?? '/'
  event.waitUntil(
    clients.matchAll({ type: 'window' }).then((windowClients) => {
      const existingClient = windowClients.find((c) => c.url === url)
      if (existingClient) return existingClient.focus()
      return clients.openWindow(url)
    })
  )
})

React Integration

function useNotifications() {
  const [permission, setPermission] = useState<NotificationPermission>(
    typeof Notification !== 'undefined' ? Notification.permission : 'denied'
  )
  const [supported] = useState(() => 'Notification' in window)

  const request = useCallback(async () => {
    if (!supported) return
    const result = await requestNotificationPermission()
    setPermission(result)
  }, [supported])

  const notify = useCallback(
    (options: NotificationOptions) => {
      if (permission !== 'granted') return null
      return showNotification(options)
    },
    [permission]
  )

  return { supported, permission, request, notify }
}

function NotificationSettings() {
  const { supported, permission, request, notify } = useNotifications()

  if (!supported) {
    return <p>Notifications are not supported by your browser</p>
  }

  return (
    <div>
      {permission === 'default' && (
        <button onClick={request}>Enable notifications</button>
      )}
      {permission === 'granted' && (
        <button onClick={() => notify({ title: 'Test', body: 'Notifications work' })}>
          Test
        </button>
      )}
      {permission === 'denied' && (
        <p>Notifications are blocked. Enable in browser settings.</p>
      )}
    </div>
  )
}

Push API and Comparison

What's Included in Integration

Comparison of Push Notification Providers

We guarantee that your implementation will pass Core Web Vitals checks and be compatible with Chrome, Firefox, Safari, and Edge. Our team has specialized in web notifications since 2019, with 15+ completed projects. The Notifications API is an open specification; we work strictly according to standards.

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.