I Built 10 Chrome Extensions in 2025 - Here's What I Learned

Source: Dev.to

The Stack & Approach

All extensions built with:

• Manifest V3 (Chrome’s latest standard)
• Vanilla JavaScript (keeping it simple and fast)
• Freemium model (generous free tier, optional Pro upgrades)
• Privacy‑first (local storage, minimal permissions)
• Gumroad/Stripe for monetization

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🔒 Privacy & Security

1. Tab Lock Pro – Biometric Tab Security

Chrome Web Store →

Problem: Sensitive tabs can be viewed by anyone when you step away.

Solution: Lock tabs with a password or biometric authentication (Face ID, Touch ID, fingerprint).

• Free: lock up to 3 tabs.
• Pro ($4.99 one‑time): unlimited locks, auto‑lock timers, panic button (Ctrl+Shift+L).

Technical highlights

• WebAuthn API for biometric authentication
• SHA‑256 password encryption
• Content‑script injection for lock screens
• Chrome storage API for persistence

// Simplified biometric auth implementation
const credential = await navigator.credentials.get({
  publicKey: {
    challenge: new Uint8Array(32),
    allowCredentials: [{ type: 'public-key', id: storedCredentialId }],
    userVerification: 'required'
  }
});

Best for: Shared computers, public workspaces, privacy‑conscious users.

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2. Privacy Shield Pro – Stop Being Tracked

Chrome Web Store →

Problem: Users are tracked by hundreds of scripts daily.

Solution: Block common trackers and mitigate fingerprinting.

• Free: blocks 15+ trackers (e.g., Google Analytics, Facebook Pixel).
• Pro ($39.99 / year): blocks 46+ trackers with advanced fingerprinting protection.

Technical highlights

• Declarative Net Request API (Manifest V3 compliant)
• Canvas fingerprinting randomization
• WebGL vendor/renderer spoofing
• Real‑time blocking dashboard

// Tracker blocking rule
chrome.declarativeNetRequest.updateDynamicRules({
  addRules: [{
    id: 1,
    priority: 1,
    action: { type: 'block' },
    condition: {
      urlFilter: '||google-analytics.com^',
      resourceTypes: ['script']
    }
  }]
});

Best for: Privacy advocates and security‑conscious developers.

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⚡ Productivity & Organization

3. Smart Tab Grouper – AI‑Powered Tab Organization

Chrome Web Store →

Problem: Too many open tabs make navigation impossible.

Solution: Automatically group tabs by domain or topic using AI, with color‑coded groups and session persistence.

Technical highlights

• Chrome Tab Groups API
• Domain pattern matching
• Simple AI categorization (Development, Social, Shopping, etc.)
• Session storage

// Auto‑group tabs by domain
const tabs = await chrome.tabs.query({});
const domainGroups = {};

tabs.forEach(tab => {
  const domain = new URL(tab.url).hostname;
  (domainGroups[domain] = domainGroups[domain] || []).push(tab.id);
});

for (const [domain, tabIds] of Object.entries(domainGroups)) {
  const groupId = await chrome.tabs.group({ tabIds });
  await chrome.tabGroups.update(groupId, {
    title: domain,
    color: getColorForDomain(domain)
  });
}

Best for: Researchers, multitaskers, and anyone who hoards tabs.

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4. Mini Journal – Sidebar Journaling

Chrome Web Store → (link omitted)

Problem: Traditional journaling apps require switching away from the browser.

Solution: A lightweight sidebar that stores entries locally.

• Free: unlimited entries, 30‑day history.
• Pro: templates, mood tracking, export options.

Technical highlights

• Chrome Side Panel API
• IndexedDB for storage
• Markdown rendering
• PDF export generation

Best for: Daily reflection and quick note‑taking.

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5. SnapNote Pro – Professional Screenshot Annotation

Chrome Web Store → (link omitted)

Problem: Capturing, annotating, and sharing screenshots involves multiple steps.

Solution: Capture and annotate in‑browser with tools for arrows, text, highlights, OCR, and cloud backup.

• Free: 50 screenshots/month.
• Pro: unlimited, OCR, cloud sync.

Technical highlights

• Chrome Tabs API for screen capture
• Canvas API for drawing annotations
• Tesseract.js for OCR (Pro)
• Cloud storage integration

// Screenshot capture
const dataUrl = await chrome.tabs.captureVisibleTab(null, { format: 'png' });

// Load into canvas for annotation
const canvas = document.getElementById('editor');
const ctx = canvas.getContext('2d');
const img = new Image();
img.onload = () => ctx.drawImage(img, 0, 0);
img.src = dataUrl;

Best for: Designers, developers, bug reporters, and remote teams.

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💬 Communication & Content

6. LinkedIn Comment AI – AI‑Powered Engagement

Chrome Web Store → (link omitted)

Problem: Crafting thoughtful LinkedIn comments is time‑consuming.

Solution: Generate authentic comments in seconds with selectable tones and lengths.

• Free: 10 comments/day.
• Pro: unlimited, voice‑training feature.

Technical highlights

• Claude AI API integration
• Context‑aware generation
• Comment history tracking
• Usage analytics

Results: Reported 247 % increase in engagement and ~15 hours saved per week.

Best for: Sales professionals, recruiters, and job seekers.

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7. QuickTranslate – Instant Translation

Chrome Web Store → (link omitted)

Problem: Switching between tabs to translate text is cumbersome.

Solution: Highlight text, right‑click, and get an instant translation popup.

• Free: 5 languages, 50 translations/day.
• Pro: 100+ languages, unlimited usage.

Technical highlights

• Context menu API
• Google Translate API integration
• Popup positioning logic
• Keyboard shortcut (Ctrl + Shift + T)

Best for: Language learners, international workers, and researchers.

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📚 Learning & Knowledge

8. AI Reading Assistant – Powered by Claude

Chrome Web Store → (link omitted)

Problem: Complex articles can be hard to digest, leading to low comprehension.

Solution: Highlight text to receive AI‑generated summaries, explanations, contextual info, and study questions. Includes free text‑to‑speech.

• Free: 5 AI operations/day.

Technical highlights

• Claude AI API for summarization and Q&A
• Text‑to‑speech via Web Speech API
• Inline overlay UI for results

Best for: Students, lifelong learners, and anyone who reads dense content.

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End of article.