Chrome & Firefox Extension Development Services

Manifest V3 experts

Custom browser extension development, done right

From a simple toolbar button to a complex cross-browser extension with a backend, we design, build, and ship extensions that pass Web Store review and survive browser updates. We know Manifest V3, service workers, content security policies, and exactly what reviewers flag — because we have been through the process with our own shipped products. See typical cost & timeline.

What we build

Extensions for Chrome, Firefox & Edge

Every build is Manifest V3, cross-browser ready, and shipped through the official stores.

01

Manifest V3 extensions

Chrome, Edge and Firefox extensions built on the current Manifest V3 standard — service workers, scoped permissions, and review-ready packaging.

02

Content scripts & service workers

Inject UI and logic into any page, run background tasks in MV3 service workers, and message between them reliably with chrome.scripting and chrome.runtime.

03

Custom popups & overlays

Polished popups, side panels, and in-page overlays built with React or vanilla JS that match your brand and feel native to the browser.

04

Automation & productivity tools

Extensions that automate repetitive web workflows, scrape and structure on-page data, and connect the browser to your backend or third-party APIs.

05

Privacy & security tools

Privacy-first extensions that block, blur, or redact sensitive content with minimal permissions and zero unnecessary data collection.

06

Web Store submission & maintenance

Listing copy, screenshots, privacy disclosures, and the review submission — plus long-term updates as browser APIs and your needs evolve.

Our process

From idea to a published extension

A clear, four-stage path from scope to a live listing — with you in the loop at every step.

Scope & spec

We map the permissions, target browsers, and exact behavior, then give you a fixed cost and timeline before any code is written.

Build & inject

We develop on Manifest V3 with content scripts, service workers, and a clean popup or overlay UI, testing against real sites as we go.

Test & harden

Cross-browser QA, permission audits, CSP checks, and edge-case testing so the extension is fast, safe, and review-ready.

Ship & maintain

We package, write the listing, submit for review, and stay on for updates as browser APIs and your product evolve.

Tech stack

Modern tooling for reliable extensions

The same stack we use to build and maintain our own published, production extensions.

TypeScript React Manifest V3 Vite @crxjs/vite-plugin chrome.scripting chrome.storage declarativeNetRequest WebExtensions API Chrome Web Store

Proof we ship

Extensions we built and published

We do not just consult on extensions — we ship our own. Two of them are live and free today.

Published

MatrixInn PiP

One-click Picture-in-Picture for any video on any site. Pop a video out into a floating window and keep watching while you work in another tab.

ChromeEdge$0

View on products

Published

MatrixInn Privacy for WhatsApp

A privacy blur mode for WhatsApp Web that hides your messages, contacts, and avatars on demand — perfect for screen-sharing or working in public.

ChromeEdgePrivacy-first

View on products

Building something specific? Read how we force Picture-in-Picture on any website, or explore our mobile app, web development, and SaaS services.

FAQ

Hiring a Chrome extension developer

Common questions about custom browser extension development and Manifest V3.

How much does custom browser extension development cost?

It depends on scope. A focused single-purpose Chrome extension is far cheaper than a cross-browser extension with a backend, authentication, and a sync service. We scope every build before quoting, so you get a fixed range up front. Our blog breaks down typical cost and timeline drivers in detail.

Do you build Manifest V3 extensions?

Yes — we build exclusively on Manifest V3, the current standard for the Chrome Web Store. That means service workers instead of background pages, the chrome.scripting API for injection, declarativeNetRequest where it fits, and strict content security policies. Every extension we ship is review-ready for the Web Store.

Can you make one extension work in Chrome, Firefox and Edge?

In most cases, yes. Chrome, Edge and other Chromium browsers share the same Manifest V3 base, so a single codebase covers them. Firefox uses the same WebExtensions APIs with a few differences, which we handle with a build step so you ship from one source to every store.

Will you submit the extension to the Chrome Web Store for us?

Yes. We handle packaging, store listing copy, screenshots, the privacy-practices disclosures, and the review submission. We have shipped published extensions, so we know what reviewers flag and how to pass review the first time.

Can I hire a Chrome extension developer for an existing project?

Absolutely. We take over existing extensions for bug fixes, Manifest V2 to V3 migrations, new features, or ongoing maintenance. Send us the source or the Web Store link and we will audit it and tell you exactly what it needs.

How do you handle user privacy and data?

Privacy-first by default. We collect only what an extension genuinely needs, document every permission, and prefer local storage over servers wherever possible. Our own published extensions store zero unnecessary user data — and we build client work to the same standard.

Start building

Hire a Chrome extension developer

Tell us what you want the browser to do. We will scope it, build it on Manifest V3, and ship it to the Web Store.

See our extensions