---
title: How to set up a React app heatmap with PostHog
date: 2025-03-07
author:
  - ian-vanagas
showTitle: true
sidebar: Docs
tags:
  - heatmaps
  - toolbar
  - product os
---

Understanding where users click your site or app shows you what interests them. A heatmap can visualize these clicks to make this analysis easier.

To help you get started, this tutorial will walk through setting up a React app with Vite, adding PostHog, accessing the heatmap, and customizing the heatmap to your needs.

## Creating a React app with Vite

First, [install Node](https://nodejs.dev/en/learn/how-to-install-nodejs/), then create a React app with Vite in your terminal, and name it whatever you want (we name ours `heatmap`).

```bash
npm create vite@latest heatmap -- --template react
cd heatmap
npm install
```

Next, in `src/App.jsx`, replace the existing code with buttons, inputs, and links we can click like this:

```jsx
// src/App.jsx
import './App.css'

function App() {
  return (
    <div className="App">
      <h1>React Heatmap</h1>
      <button>Click me</button>
      <input type="text" />
      <a href="https://www.posthog.com">Go to PostHog</a>
    </div>
  )
}

export default App
```

When we run `npm run dev`, this gives us a basic React app which we can use to test PostHog's heatmap functionality.

![App](https://res.cloudinary.com/dmukukwp6/image/upload/Clean_Shot_2025_03_07_at_11_00_50_2x_6efa422087.png)

## Adding PostHog

Next, we will add PostHog to your React app. This requires a PostHog instance, which you can [sign up for (for free)](https://app.posthog.com/signup). Once you have a PostHog instance, go back to your terminal and install `posthog-js`:

```bash
npm i posthog-js
```

After installing, go to `src/main.jsx` and set up the PostHog provider. To do this:

1. Import `posthog` from `posthog-js` and the `PostHogProvider` from `@posthog/react`
2. Initialize `posthog` with your project API key and host from [your project settings](https://us.posthog.com/settings/project).
3. Wrap your `App` component in the `PostHogProvider` with the initialized `posthog` as a `client` property

```jsx
// src/main.jsx
import React from 'react'
import ReactDOM from 'react-dom/client'
import App from './App.jsx'
import './index.css'
import posthog from 'posthog-js'
import { PostHogProvider } from '@posthog/react'

posthog.init('<ph_project_api_key>', {
  api_host: '<ph_client_api_host>',
  defaults: '<ph_posthog_js_defaults>'
})

ReactDOM.createRoot(document.getElementById('root')).render(
  <React.StrictMode>
    <PostHogProvider client={posthog}>
      <App />
    </PostHogProvider>
  </React.StrictMode>,
)
```

Once done, run `npm run dev` again then go to your app and click the button, enter some text into the input, and click the link. You should see events for these in your PostHog instance.

<ProductScreenshot
  imageLight="https://res.cloudinary.com/dmukukwp6/image/upload/Clean_Shot_2025_03_07_at_11_05_34_2x_65b7249857.png"
  imageDark="https://res.cloudinary.com/dmukukwp6/image/upload/Clean_Shot_2025_03_07_at_11_05_46_2x_8e363e9e25.png"
  alt="Events in PostHog"
  classes="rounded"
/>

## Launching your toolbar to access the heatmap

With our React app and PostHog set up as well as some data, we can get a heatmap of this data using the toolbar. 

In PostHog, click the [Toolbar tab](https://us.posthog.com/toolbar) on the left menu, then add `http://localhost:5173` to the authorized URLs, and click **Launch**. This takes you to your site with the PostHog toolbar active.

![Toolbar](https://res.cloudinary.com/dmukukwp6/image/upload/Clean_Shot_2025_03_07_at_11_09_51_2x_8b962cbfd6.png)

To activate the heatmap, click the heatmap icon in the toolbar. This highlights the areas of your app that users are clicking on. For this tutorial, we also recommend enabling the **Clickmaps** option so you can see what elements users are clicking on.

![Heatmap](https://res.cloudinary.com/dmukukwp6/image/upload/Clean_Shot_2025_03_07_at_11_12_13_2x_6b75bd4a3e.png)

## Understanding the heatmap

With the heatmap open, you see both hotspots and clickmaps highlighted in shades of green to red. Here's what the numbers mean:

- The numbers over the elements are how many times they were clicked over the last 7 days.
- The number next to the 😡 emoji is the number of rage clicks for that element.

When you click an element, you get a modal with different options:

1. Details about the selected option, like its text and DOM location.
2. Stats including clicks and ranking of most clicked on the page.
3. The ability to [create an action](/tutorials/how-to-capture-events-the-easy-way).

## Changing the heatmap settings

You can also change the settings for your heatmap by using the menu that appears when you click the heatmap icon. This enables you to:

- Change the events list to contain more pages using wildcards (`*`). For example, if you wanted to see the heatmap for the same elements across all blog pages, you could use `/blog/*`.
- Change the length of time the heatmap generates from. The default is 7 days.
- See all the elements in the heatmap and load more.
- Whether to aggregate by event count or unique users.
- Viewport size to include in the heatmap.

Once all these settings are set as you prefer, you've set up a heatmap for your React app. You can use it to analyze user behavior in your app.

## Further reading

- [Using the PostHog Toolbar to visualize behavior and create actions](/tutorials/toolbar)
- [How to create new events the easy way](/tutorials/how-to-capture-events-the-easy-way)
- [How to use session recordings to get a deeper understanding of user behavior](/tutorials/explore-insights-session-recordings)

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