> For the complete documentation index, see [llms.txt](https://docs.mapbox.com/mapbox-gl-js/llms.txt)
# Add a hover tooltip that follows the mouse pointer
This example shows how to use a [`Popup`](https://docs.mapbox.com/mapbox-gl-js/api/markers/#popup) with custom event listeners to create a tooltip that follows the mouse pointer when hovering over a polygon feature.
It uses [`Map.addInteraction`](https://docs.mapbox.com/mapbox-gl-js/api/map/#map#addinteraction) to detect `mousemove` events over the `state-fills` layer, updating the popup's position and content based on the feature being hovered. When the mouse leaves the feature, a [`Map.on('mouseleave')`](https://docs.mapbox.com/mapbox-gl-js/api/map/#map.event:mouseleave) event listener removes the popup from the map.
To add a highlight effect to complement the tooltip, see the [Create a hover effect](https://docs.mapbox.com/mapbox-gl-js/example/hover-styles/) example
> Example code:
**JavaScript**
```html
Add a hover tooltip that follows the mouse pointer
```
**React**
```jsx
import React, { useEffect, useRef } from 'react';
import * as mapboxgl from 'mapbox-gl/esm';
import 'mapbox-gl/dist/mapbox-gl.css';
const MapboxExample = () => {
const mapContainerRef = useRef();
const mapRef = useRef();
useEffect(() => {
mapRef.current = new mapboxgl.Map({
// TO MAKE THE MAP APPEAR YOU MUST
// ADD YOUR ACCESS TOKEN FROM
// https://account.mapbox.com
accessToken: 'YOUR_MAPBOX_ACCESS_TOKEN',
container: mapContainerRef.current,
// Choose from Mapbox's core styles, or make your own style with Mapbox Studio
style: 'mapbox://styles/mapbox/standard',
center: [-100.486052, 37.830348],
zoom: 2
});
// Create a popup, but don't add it to the map yet
const popup = new mapboxgl.Popup({
closeButton: false,
closeOnClick: false,
offset: [0, -20]
});
mapRef.current.on('style.load', () => {
mapRef.current.addSource('states', {
type: 'geojson',
data: 'https://docs.mapbox.com/mapbox-gl-js/assets/us_states.geojson'
});
// The feature-state dependent fill-opacity expression will render the hover effect
// when a feature's hover state is set to true.
mapRef.current.addLayer({
id: 'state-fills',
type: 'fill',
source: 'states',
layout: {},
paint: {
'fill-color': '#627BC1',
'fill-opacity': 0.5
}
});
mapRef.current.addLayer({
id: 'state-borders',
type: 'line',
source: 'states',
layout: {},
paint: {
'line-color': '#627BC1',
'line-width': 2
}
});
// use addInteraction for quick access to the feature under the mouse
mapRef.current.addInteraction('state-fills-mousemove', {
type: 'mousemove',
target: {
layerId: 'state-fills'
},
handler: (e) => {
// Position the popup at the cursor location and show it
popup
.setLngLat(e.lngLat)
.setHTML(`${e.feature.properties.STATE_NAME}`)
.addTo(mapRef.current);
}
});
// Use a standard Mapbox GL JS event listener for mouseleave to hide the popup
mapRef.current.on('mouseleave', 'state-fills', () => {
popup.remove();
});
});
}, []);
return ;
};
export default MapboxExample;
```