DEV Community

Cover image for I Built a Chrome Dictionary Extension in 2 Weeks:
shantanu basu
shantanu basu

Posted on

I Built a Chrome Dictionary Extension in 2 Weeks:

From Local Hacking to 4 Browser Stores

TL;DR: Shipped a Chrome extension that fetches word definitions from a free API,
published to Chrome Web Store, and now expanding to Firefox, Opera, and Brave.
Here's what I learned.


Why I Built This

I spend a lot of time reading articles and documentation online. Sometimes I
encounter words I want to quickly understand without losing my flow. Most
dictionary extensions either clutter your toolbar or charge money.

So I decided to build one myself.

This wasn't meant to be a unicorn idea. It was meant to be useful, small,
and shippable
. A perfect learning project for understanding Chrome extensions,
browser APIs, and the publishing process.


The Tech Stack (Surprisingly Simple)

  • Manifest v3 (Chrome's modern extension standard)
  • Vanilla JavaScript (no frameworks, no build tools)
  • Free Dictionary API (zero rate limits, rich data)
  • HTML + CSS (deep blue theme #003D82)

Total size: ~50KB. No dependencies. Runs offline once loaded.


Core Features

1. Right-Click Context Menu

Right-click any word → "Look up in Dictionary" appears → Popup shows definition

Simple. Works everywhere.

2. Definition Popup

Clean popup showing:

  • Word & pronunciation
  • Part of speech (noun, verb, etc.)
  • Primary definition
  • Example usage
  • API attribution

Deep blue background, white text. Distraction-free.

3. Free Dictionary API

Used Free Dictionary API for data:

  • No authentication needed
  • No rate limits
  • Returns pronunciation, examples, multiple meanings
  • Stable uptime for years

Why this over OpenAI/Anthropic? For this use case, simplicity + reliability >
advanced features.


The Publishing Journey

This is where it got interesting.

Chrome Web Store (1 Week)

What I learned: Building took 1 week. Publishing prep took another week.

  1. Create Chrome developer account ($5)
  2. Prepare assets (icon, screenshots, description)
  3. Upload ZIP file
  4. Google's automated review: 1-3 hours
  5. Live on Chrome Web Store ✓

The tricky part wasn't the code—it was getting the screenshots right, writing
a description that passes Google's guidelines, and understanding what "sensitive
permissions" mean.

Firefox (2-3 Days)

Firefox is stricter about privacy. They literally ask: "Does your extension
collect user data?"

Honest answer: No. This extension doesn't store anything.

Result: Approved in 2 days.

Opera & Brave (Bonus)

  • Opera: Same review process as Chrome, 1-3 days
  • Brave: Automatically syncs with Chrome Web Store (instant ✓)

What I Actually Learned

1. Publishing is Harder Than Building

The extension logic? A few hours. Getting it published to 4 stores? A week.

Screenshot requirements, description length limits, icon sizing, privacy policies
for each store—it adds up. Plan accordingly.

2. Manifest v3 is the Future

Manifest v2 (older standard) is deprecated. Manifest v3 forces better practices
(no inline scripts, explicit permissions). Learn v3 from the start if building
extensions in 2026+.

3. Free APIs are Gold for Indie Projects

The Free Dictionary API has been running for years with zero cost. For side
projects, this is perfect. You avoid vendor lock-in and zero payment friction.

4. Context Menus > Toolbar Buttons

Most people never click toolbar icons. But everyone right-clicks. This one design
decision probably increased discoverability 10x.


The Numbers

  • Build time: 1 week
  • Publishing time: 1 week
  • Total cost: $5 (Chrome developer account)
  • Extension size: 50KB
  • Dependencies: 0
  • Uptime so far: 100%

What's Next

v1.1 (coming this week):

  • Search box with autocomplete suggestions
  • Pronunciation audio
  • Better error handling

Long-term ideas:

  • Synonyms & antonyms
  • Word history/etymology
  • Theme toggle
  • Offline dictionary fallback

But I'm shipping v1.1 first and waiting for user feedback before going further.


If You're Thinking About Building a Browser Extension

Here's my advice:

Do:

  • Build something you would actually use
  • Keep scope small (one thing, done well)
  • Learn Manifest v3 properly (one-time investment)
  • Test across multiple websites before publishing
  • Plan your publishing timeline early (it's longer than you think)

Don't:

  • Over-engineer for features nobody asked for
  • Ignore privacy implications (regulators care, users care)
  • Assume old extension knowledge (Manifest v2 is deprecated)
  • Underestimate app store review requirements

The Real Win Here

This wasn't about building the world's best dictionary. It was about:

  • Executing an idea end-to-end
  • Shipping to production
  • Publishing across multiple platforms
  • Learning how app stores work
  • Building portfolio proof that I can ship

That's worth more than any feature.


Resources That Helped


Now What?

For you: If you've been thinking about building a browser extension,
this is your sign. It's easier than you think.

For me: Next up is a stock announcement tracker for Indian markets (Q3 goal).
Similar journey: ship → iterate → publish.

Want to try the extension? Get it on Chrome Web Store

What's your first browser extension idea? Drop it in the comments. 👇


Tags: #ChromeExtension #WebDevelopment #IndieHacking #Shipping

Top comments (0)