---
title: Custom Filter Link
toc: false
---

# Custom Filter Link Example

This example demonstrates how to use a query string parameter to mark a link as "active" or not. This is a common technique when implementing a filter in a sidebar where you're browsing products.

## Preview

Open this example on [StackBlitz](https://stackblitz.com):

[![Open in StackBlitz](https://developer.stackblitz.com/img/open_in_stackblitz.svg)](https://stackblitz.com/github/remix-run/react-router/tree/main/examples/custom-filter-link?file=src/App.tsx)
