Neighbor Detective

Overview

Neighbor Detective is a small browser add-on that helps me inspect neighborhood statistics quickly from a Dutch postcode. The main idea is simple: take the first 4 digits of a postcode and show useful area-level information without having to open separate sites and search manually.

The Problem

When I want to understand an area, I usually only need a quick first pass. Opening different pages, copying a postcode, and checking several statistics one by one is slow and breaks the flow.

For many use cases, the first 4 digits of the postcode are already enough to get a basic neighborhood picture. I wanted a faster way to get that context directly from the browser.

The Solution

I built a Firefox add-on that focuses on the first 4 digits of a postcode and turns that into a lightweight neighborhood lookup tool.

• Postcode-first flow: use the first 4 digits as the main input
• Quick statistics: show useful neighborhood-level numbers in one place
• Lightweight interaction: avoid opening multiple tabs for a basic area check
• Browser-native usage: keep the tool simple and available where I already work

Key Features

Fast Area Lookup

• Enter or detect the first 4 postcode digits
• Show relevant neighborhood statistics immediately
• Keep the interaction simple enough for repeated daily use

Lightweight Extension UX

• Built as a small browser add-on instead of a full web app
• Focused on speed and clarity over too many filters
• Easy to install and test directly inside Firefox

Technical Highlights

• Extension Platform: Firefox WebExtension
• Frontend: JavaScript, HTML, and CSS
• Product Scope: small utility focused on one specific lookup job

Current State

The first version is already published in Firefox Add-ons and has been accepted. Right now the project is in the useful-tool stage: narrow scope, clear purpose, and good enough to start learning from real usage.

The next step is deciding whether this stays a focused Firefox-only tool or grows into a broader postcode research utility with more datasets and better presentation.