Custom Browser Extension Development

The browser is where your team already works. Extensions put your tools right there — scraping the retyping out of workflows, connecting internal systems to the pages people are looking at, or shipping a product to millions of Chrome users.

We build and ship our own extensions (including CalmTab) as well as clients' — so we know Manifest V3, store review, and cross-browser quirks from production experience, not blog posts.
Discuss Your Extension Idea See Our Work

Extensions We Build

For Chrome, Firefox, Edge, and Safari — from single-team internal tools to published Web Store products.

Internal Workflow Tools

Overlay your CRM data on LinkedIn, autofill your systems from supplier portals, push data from any web page into your database with one click. Hours of copy-paste, gone.

Product Extensions

A browser extension can be the product — or the growth channel for one. We build store-ready extensions with onboarding, sync, and licensing baked in.

New Tab & Productivity Extensions

Dashboards, quick-access tools, and focus aids that live in the browser chrome itself — like our own CalmTab.

Integration Bridges

When a third-party web app has no API, an extension can be the bridge — reading and writing through the interface your team already uses, safely and reliably.

Manifest V3 Migrations

Got an older extension broken by Chrome's Manifest V3 requirements? We migrate legacy extensions so they stay on the store and keep working.

Enterprise Deployment

Private extensions force-installed across your organisation via Google Workspace or group policy — no store listing, no user setup.

Why Extensions Are a Quiet Superpower

Most business software makes people switch context: leave the page, open the tool, copy things across, go back. A browser extension deletes that loop. The tool appears exactly where the work is happening — on the supplier's portal, the job board, the CRM record — and acts on what's already on screen.

For a surprising number of "we need an app" conversations, the honest answer is actually "you need an extension." They're faster to build, instant to distribute (especially internally), and they meet your team inside the tools they already live in.

Built to survive store review

Chrome Web Store review is notoriously picky: permissions must be minimal and justified, remote code is banned, and Manifest V3 rules keep tightening. We design for compliance from the start — minimal permissions, clean privacy disclosures, and store listings that pass review rather than bouncing for weeks.

Cross-browser without triple cost

Chrome, Edge, and Firefox share most of the WebExtensions API; Safari needs a wrapper via Xcode. We build from a single codebase that targets all of them, so supporting a second browser is a build step, not a second project.

How We Work

1

Discovery

Which workflow, which sites, which browsers? We scope the exact loop the extension removes. Free, no obligation.

2

Specification & Fixed Quote

Permissions, browsers, sync, and store strategy in writing — with a fixed price attached.

3

Build & Test

You sideload working builds from early in the project and test on your real workflows, not demo pages.

4

Publish & Maintain

Store submission, review wrangling, and updates as browsers evolve — handled by the developer who built it.

Browser Extension FAQs

How much does browser extension development cost?

Simple single-purpose extensions start around the low thousands. Extensions with backend sync, accounts, or cross-browser support typically run higher — always with a fixed quote before any build work begins.

Do extensions work on Chrome, Firefox, Edge, and Safari?

Yes. Chrome, Edge, and Firefox share most of the modern WebExtensions API, so one codebase covers all three. Safari requires packaging through Xcode, which we handle if your users need it.

Can an extension be private to our company?

Yes — extensions can be distributed privately and force-installed across your organisation through Google Workspace or group policy, so your team gets it automatically and nobody outside your business ever sees it.

What is Manifest V3, and does it affect us?

Manifest V3 is Chrome's current extension platform — stricter on permissions, background processing, and remote code. New extensions must use it, and older Manifest V2 extensions have been phased out. Everything we build is V3-compliant from the start, and we migrate legacy extensions too.

Got a workflow the browser could do for you? Let's scope it out.

Book a Free Consultation