Chrome, Edge & Firefox Extension Development

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 prepared for Web Store review and maintained as browser APIs change. 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, Edge & Firefox

We build on Manifest V3 and ship 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 only the data collection the extension needs.

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.

Firefox extension development

Firefox extensions, and Chrome-to-Firefox ports

Firefox runs the same WebExtensions APIs as Chrome, but not identically. We build Firefox extensions from scratch or port an existing Chrome extension, keeping one shared codebase for every store. Our Firefox extension development guide covers the differences in detail.

Firefox-specific Manifest V3: background scripts instead of a service worker, the promise-based browser.* namespace, and host permissions the user grants.
Chrome-to-Firefox ports: we replace Chrome-only APIs, adapt the manifest and background logic, and test every feature in Firefox.
addons.mozilla.org submission: listing, privacy disclosures, and the source-code package Mozilla reviewers ask for when code is bundled.
Firefox for Android: we check which APIs are available on mobile Firefox and test there too when you want Android support.

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-bid quote 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

Browser QA, permission audits, CSP checks, and edge-case testing before we submit for review.

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

A typical stack for our extension work. We adapt it to your project.

TypeScript React Manifest V3 Vite 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 on the Chrome Web Store 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 package preparedFree

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.

ChromeEdge package preparedPrivacy-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 or Firefox 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 on Manifest V3, the current Chrome Web Store standard, and prepare each extension for Web Store review. That means service workers instead of background pages, the chrome.scripting API for injection, declarativeNetRequest where it fits, and strict content security policies.

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

Yes. Chrome and Edge share the same Manifest V3 base, so one codebase covers both. Firefox uses the same WebExtensions APIs with a few differences (the browser.* namespace, background scripts instead of service workers, and host permissions the user grants), so we keep one shared codebase and a small per-browser build step.

Do you build Firefox extensions and publish them on addons.mozilla.org?

Yes. We build Firefox extensions on Manifest V3 (or V2 where Firefox still supports it and it suits the project), test them in Firefox and Firefox for Android, and prepare the addons.mozilla.org listing and review submission, including the source-code package Mozilla asks for when code is bundled or minified.

Can you port my existing Chrome extension to Firefox?

Yes. We audit the Chrome extension, replace Chrome-only APIs, adjust the manifest and background logic for Firefox, and test every feature in Firefox before submitting it to addons.mozilla.org. You keep one codebase for both stores.

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, and we know what reviewers commonly flag.

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 extensions are built to collect only what they need, and we aim for the same standard on client work.

Related guides

Start building

Hire a Chrome or Firefox 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.

Start a project → See our extensions

Chrome, Edge & Firefox Extension Development Services