How I Built a Chrome Extension to Extract Emails and Phone Numbers – A Developer’s Journey

As a fullstack developer, I’m always on the lookout for tools that save time and automate repetitive tasks. One thing I noticed early in my career is that collecting contact information—emails and phone numbers—from websites can be tedious, especially if you’re doing it manually. Whether it’s for outreach, research, or building a curated contact list, manually scanning pages is slow, error-prone, and frankly, exhausting.

That’s when I decided to create my very first Chrome extension: an Email and Phone Extractor. This project wasn’t just about scraping data; it was about building a lightweight, user-friendly, and reliable tool that anyone could use ethically and efficiently.

You can add the Extension to your chrome browser here!

Why I Built This Extension

The idea came from my own workflow frustrations. I often needed contact information from company websites, portfolio pages, or public directories. Copying and pasting each email or number was draining. I wanted a tool that would scan the page automatically, organize the results, and give me a clean output I could use immediately.

I envisioned a simple Chrome extension that could:

1. Detect all email addresses and phone numbers on the current page.
2. Provide a clear interface to view, copy, or save the extracted contacts.
3. Handle dynamically loaded content without slowing down the browser.
4. Be easy for anyone to install and use, even without a technical background.

Getting Started with Chrome Extension Development

Building a Chrome extension was a new adventure for me. I started by diving into Chrome’s extension APIs. Chrome extensions have three main components:

1. Manifest file – defines the extension’s metadata and permissions.
2. Content scripts – allow the extension to interact with the web page’s DOM.
3. Background scripts – handle messaging, persistent storage, and long-running tasks.

Building a Clean and Intuitive Interface

One of my main goals was user experience. I wanted the extension to be simple but functional. The popup displays:

1. Emails and phone numbers in separate sections
2. A button to copy all results to the clipboard
3. A count of unique emails and phone numbers

Optional filters to remove duplicates

I wanted users to feel in control. They can extract all contacts with a single click and copy them without dealing with messy page content.

Ethical Considerations

While the extension can extract public information, I wanted to make ethical use clear. I added a disclaimer reminding users to respect privacy laws and not misuse the tool for spam. Emails and phone numbers collected should only be used for legitimate purposes, like reaching out professionally or conducting research.

Challenges Along the Way

Building this extension wasn’t without hurdles:

1. Handling large pages: Some websites have thousands of DOM nodes. I had to ensure the extension scanned efficiently without freezing the browser.
2. Dynamic content: Modern sites often load data asynchronously. Mutation observers were critical here.
3. False positives: Regex sometimes matched text that looked like emails or phone numbers but weren’t. I added filtering and validation to minimize this.
4. Cross-browser quirks: While building primarily for Chrome, I ensured that the extension’s logic could be adapted for other Chromium-based browsers like Edge and Brave.

Real-Life Use Cases

Here are some ways developers and professionals can benefit from this extension:

1. Sales and Business Development: Quickly gather leads from public directories and websites.
2. Recruitment: Extract contact information of potential candidates from company pages or LinkedIn profiles (respecting platform policies).
3. Networking: Build professional connections by compiling contact lists for outreach.
4. Research & Data Collection: Academics and researchers can collect emails for surveys or collaborations.

Because of these use cases, the extension isn’t just a productivity tool—it’s a way to automate routine tasks and focus on what truly matters.

Sharing My Work

After testing extensively and refining the features, I published the extension on the Chrome Web Store. The process taught me a lot about packaging, metadata, and compliance with Google’s publishing rules. I also shared it with friends and colleagues, who found it immediately useful.

For those interested, you can try it here: Email & Phone Extractor Chrome Extension

Lessons Learned

Building this Chrome extension was more than a coding exercise—it was a lesson in user experience, problem-solving, and ethical development. Some key takeaways:

1. Even small projects can have complex technical challenges
2. Regex is powerful but requires careful testing
3. Handling dynamic content is critical for modern web tools
4. Ethical considerations should never be overlooked

Conclusion

Creating the Email and Phone Extractor Chrome extension was a fulfilling journey. It started as a personal tool to save time and evolved into a polished extension that can help other developers, researchers, and professionals streamline their workflows.

If you’re a developer looking for a practical project, Chrome extension development is a fantastic way to combine front-end skills with practical problem-solving. And who knows—you might just build a tool that thousands of people end up using!