Guides / Ideas and launching

20 Chrome Extension Ideas (and How Extensions Are Built and Published)

Twenty Chrome extension ideas with who they're for, the first version, how they earn and the hard part, plus how Manifest V3 and store review work.

Mythex Team · 2026-10-22 · 9 min read

Good Chrome extension ideas do one narrow job inside pages people already use: clean up a cluttered view, save something to a tool, fill in a repeated form, or add a missing feature to a site. That's not just good product sense; the Chrome Web Store's quality guidelines require each extension to have a single, narrow purpose. Below are twenty ideas, each with who it's for, the first version, how it could make money and the hard part, followed by how extensions are built (Manifest V3), published and paid for, as of October 2026.

For web app ideas instead, see micro-SaaS ideas or web app ideas.

The 20 ideas at a glance

Reading, research and learning

1. Research tab sessions

• For: Students and researchers with 40 tabs open.
• First version: Save a window's tabs as a named session with notes; reopen later.
• Makes money: Free, with a paid plan for sync across devices.
• Hard part: A crowded category; pick a twist, like sessions tied to a deadline.

2. Site-specific focus mode

• For: People who lose hours to one or two sites.
• First version: Hide feeds or recommendations on chosen sites during set hours, with a "five more minutes" button.
• Makes money: One-off payment or small subscription for schedules and stats.
• Hard part: Sites change their pages, which breaks hiding rules.

3. Reading view with spacing controls

• For: Readers who find dense pages hard, including some people with dyslexia.
• First version: Simplified article view with adjustable font, letter spacing, line height and background colour.
• Makes money: Often free; schools and organisations may pay for managed deployment.
• Hard part: Extracting the main text from messy pages.

4. Page highlights and notes

• For: Researchers and writers who want highlights that stay on the page.
• First version: Highlight text, add notes, see them on revisit, and export a project's notes.
• Makes money: Subscription for sync and export.
• Hard part: Re-finding highlights when the page changes slightly.

5. Vocabulary saver for language learners

• For: People learning a language by reading real websites.
• First version: Double-click a word to save it with the sentence it came from; review saved words as flashcards. How to build a flashcard app covers the review side.
• Makes money: Subscription for review features and sync.
• Hard part: Translation needs a translation or AI API, which costs money per request; budget for it.

6. Citation copier

• For: Students and journalists.
• First version: One click copies the page's title, author, date and URL in a chosen citation style.
• Hard part: Metadata is often missing; let users edit it.

Shopping and everyday

7. Unit price calculator for grocery sites

• For: Shoppers comparing pack sizes.
• First version: On one supermarket's site, show price per kilo or per item next to each product, and sort by it.
• Makes money: Small one-off payment, or free.
• Hard part: Each shop's pages differ and change; start with one shop. Read the site's terms first.

8. Meeting link tidy-up

• For: Remote workers with links scattered across calendar invites and emails.
• First version: Detect meeting links on a page and show a clean "join" button with the time in your zone.
• Hard part: Ask for the fewest permissions possible.

9. Listing-to-spreadsheet saver

• For: People house hunting, car hunting or comparing rentals across several sites.
• First version: A button that saves a listing's price, location, link and your notes to one comparison table.
• Makes money: Subscription during the few months someone is searching.
• Hard part: Many listing sites limit automated collection in their terms. Save only what the user is looking at, with the user clicking.

10. Time zone converter on selection

• For: Remote teams and anyone booking calls abroad.
• First version: Select a time like "3pm EST" on any page and see it in your local time.
• Hard part: Time formats.

Work and teams

11. Saved-replies inserter

• For: Support staff, recruiters and anyone who types the same replies all day.
• First version: A library of replies with placeholders (name, order number); insert into any text box with a shortcut.
• Makes money: Per user per month, with a shared team library on a paid plan.
• Hard part: Text boxes behave differently across web apps; test the ones your users use.

12. Save-to-CRM button

• For: Freelancers and small sales teams who find leads on websites.
• First version: On any company page, save the name, URL and a note as a lead in your own simple CRM. Build the CRM side with the CRM builder; see how to build a CRM.
• Makes money: Subscription to the CRM; the extension is a feature.
• Hard part: Don't collect personal data from sites against their terms; let the user choose what to save.

13. Screenshot to annotated bug report

• For: Product and QA teams.
• First version: Capture the visible page, draw an arrow, add a note, and send it with the URL and browser details to a simple bug list. How to write a good bug report covers what to include.
• Makes money: Per team per month.
• Hard part: Many tools exist; connect to wherever users already track bugs.

14. Job application clipper

• For: Job seekers applying on many sites.
• First version: Save a job ad's title, company, link and closing date to a tracker with one click. See how to build a job application tracker.
• Makes money: Small subscription; users leave once hired.
• Hard part: Job sites differ a lot.

15. New tab dashboard from your own data

• For: Small business owners who want today's numbers every time they open a tab.
• First version: The new tab page shows today's orders, bookings or sign-ups from your own app. Build the data side with the dashboard builder.
• Makes money: As part of the app it reads from.
• Hard part: Keeping API keys out of the extension; the extension should talk to your own back end, not hold secret keys.

16. Writing checker for one style guide

• For: Content teams with a house style.
• First version: Highlight banned words, wrong product names and spelling variants in any text box, based on a list the team edits.
• Makes money: Per team per month.
• Hard part: Never lagging while typing.

17. Page change watcher

• For: People waiting for a page to change: a results page, a stock status, a policy.
• First version: Pick a section of a page and get notified when it changes.
• Makes money: Free tier with a few watches, paid for more and faster checks.
• Hard part: In Manifest V3, background checks run from a service worker that only wakes on events or alarms, and only while Chrome is running. Reliable, frequent checks often need a server.

Developers and designers

18. Form auto-filler for test data

• For: Developers and testers filling the same forms all day.
• First version: Fill any form with realistic fake data (names, addresses, test card numbers from a payment provider's docs) with one click.
• Makes money: Small one-off or team licence.
• Hard part: Not filling real forms by mistake; limit it to chosen domains.

19. JSON and API response viewer

• For: Developers reading raw API responses in the browser.
• First version: Pretty-print JSON, collapse sections, search keys and copy paths. What is JSON explains the format.
• Hard part: Very crowded; stand out on one feature, like comparing two responses.

20. Accessibility quick checks

• For: Designers and developers reviewing a page.
• First version: Flag images without alt text, low contrast text and missing form labels on the current page. How to make your website accessible lists the basics.
• Makes money: Team plans with saved reports.
• Hard part: Automated checks catch only some problems; say so.

How Chrome extensions are built (Manifest V3)

According to Google's getting-started docs, extensions use the same technologies as websites: HTML, CSS and JavaScript, plus Chrome's extension APIs. The main parts are:

• manifest.json: the one required file. It holds the extension's name and version, its permissions, and which scripts run where.
• Service worker: runs in the background to handle browser events. It has no access to page content and only runs when needed.
• Content scripts: JavaScript that runs inside web pages, for reading or changing what's on the page.
• Popup or toolbar action: what happens when someone clicks your icon.
• Side panel: a panel beside the page for a fuller interface.

Two Manifest V3 rules affect what you can build, as explained in Google's Manifest V3 overview:

• No remotely hosted code. An extension can only run JavaScript included in its package. You can still fetch data from your server, but not new code.
• Background work is event-driven. Service workers replace always-on background pages, so long-running background tasks are harder. Anything that must run on a schedule reliably may need a server.

Manifest V2 is gone: Google's deprecation timeline says the store stopped accepting new MV2 extensions in 2022 and removed the remaining ones on August 31, 2026. Old tutorials using MV2 won't work for new extensions.

Where AI tools fit

AI coding assistants can write extension code, which you test by loading the folder as an unpacked extension with developer mode on. AI app builders like Mythex build web apps and websites, not extensions, but they suit the companion web app many of these ideas need: accounts, a database, a dashboard and payments. Keep secret API keys on that server, never in the extension, because anyone can read an extension's files. How to keep API keys safe explains why.

Publishing on the Chrome Web Store

1. Register as a developer. Google's registration page says you open the developer dashboard, agree to the developer agreement and policies, and pay a one-time registration fee. The page doesn't state the amount, so confirm it in the dashboard. Google also notes the account email can't be changed later.
2. Prepare the listing: name, description, icon, screenshots and a privacy policy if you handle user data. How to write terms of service and a privacy policy helps.
3. Ask for as few permissions as possible. Google's review process page says broad host permissions (like access to all sites), sensitive permissions (like tabs, cookies or webRequest), large or hard-to-review code, and new developer accounts can all lengthen review. Obfuscated code isn't allowed.
4. Submit and wait. Google says most reviews finish within a few days, though some take up to a few weeks.
5. Keep to one purpose. The quality guidelines require a single, narrow purpose and rule out extensions whose main purpose is serving ads.

How to charge for an extension

The Chrome Web Store no longer handles payments for extensions; Google deprecated its built-in payments, so paid extensions use another payment processor. The usual setup is:

• A small web app where users sign up and pay, using a provider such as Stripe or Paddle. How to add payments to your app and Stripe vs Paddle vs Lemon Squeezy compare the options.
• The extension signs in to that web app and checks whether the user is on a paid plan.

Ideas 11 to 15 fit this model best. Whichever you pick, start from a problem you have daily in your own browser, and validate it before you build.