Camera

expo-camera provides a React component that renders a preview for the device's front or back camera. The camera's parameters like zoom, auto focus, white balance and flash mode are adjustable. With the use of Camera, one can also take photos and record videos that are then saved to the app's cache. Morever, the component is also capable of detecting faces and bar codes appearing in the preview. Run the example on your device to see all these features working together!

Platform Compatibility

Android Device	Android Emulator	iOS Device	iOS Simulator	Web

Android devices can use one of two available Camera APIs: you can opt-in to using Camera2 with the useCamera2Api prop.

Installation

Terminal

→ npx expo install expo-camera

If you're installing this in a bare React Native app, you should also follow these additional installation instructions.

Usage

Only one Camera preview can be active at any given time. If you have multiple screens in your app, you should unmount Camera components whenever a screen is unfocused.

Basic Camera usage

import { Camera, CameraType } from 'expo-camera';
import { useState } from 'react';
import { Button, StyleSheet, Text, TouchableOpacity, View } from 'react-native';

export default function App() {
  const [type, setType] = useState(CameraType.back);
  const [permission, requestPermission] = Camera.useCameraPermissions();

  %%placeholder-start%%if (!permission) ... %%placeholder-end%%if (!permission) {
    // Camera permissions are still loading
    return <View />;
  }

  %%placeholder-start%%if (!permission.granted) ... %%placeholder-end%%if (!permission.granted) {
    // Camera permissions are not granted yet
    return (
      <View style={styles.container}>
        <Text style={{ textAlign: 'center' }}>We need your permission to show the camera</Text>
        <Button onPress={requestPermission} title="grant permission" />
      </View>
    );
  }

  function toggleCameraType() {
    setType(current => (current === CameraType.back ? CameraType.front : CameraType.back));
  }

  return (
    <View style={styles.container}>
      <Camera style={styles.camera} type={type}>
        <View style={styles.buttonContainer}>
          <TouchableOpacity style={styles.button} onPress={toggleCameraType}>
            <Text style={styles.text}>Flip Camera</Text>
          </TouchableOpacity>
        </View>
      </Camera>
    </View>
  );
}

%%placeholder-start%%const styles = StyleSheet.create({ ... }); %%placeholder-end%%const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
  },
  camera: {
    flex: 1,
  },
  buttonContainer: {
    flex: 1,
    flexDirection: 'row',
    backgroundColor: 'transparent',
    margin: 64,
  },
  button: {
    flex: 1,
    alignSelf: 'flex-end',
    alignItems: 'center',
  },
  text: {
    fontSize: 24,
    fontWeight: 'bold',
    color: 'white',
  },
});

Web Support

Luckily most browsers support at least some form of web camera functionality, you can check out the web camera browser support here. Image URIs are always returned as base64 strings because local file system paths are not available in the browser.

Chrome `iframe` usage

When using Chrome versions 64+, if you try to use a web camera in a cross-origin iframe nothing will render. To add support for cameras in your iframe simply add the attribute allow="microphone; camera;" to the iframe element:

<iframe src="..." allow="microphone; camera;">
  <!-- <Camera /> -->
</iframe>

API

import { Camera } from 'expo-camera';

Component

`Camera`

Type: Component<CameraProps>

Props

`autoFocus`

Optional • Type: boolean | number | AutoFocus • Default: AutoFocus.on

State of camera auto focus. Use one of AutoFocus.<value>. When AutoFocus.on, auto focus will be enabled, when AutoFocus.off, it won't and focus will lock as it was in the moment of change, but it can be adjusted on some devices via focusDepth prop.

`barCodeScannerSettings`

Optional • Type: BarCodeSettings

Settings exposed by BarCodeScanner module. Supported settings: barCodeTypes.

Example

<Camera
  barCodeScannerSettings={{
    barCodeTypes: [BarCodeScanner.Constants.BarCodeType.qr],
  }}
/>

`faceDetectorSettings`

Optional • Type: object

A settings object passed directly to an underlying module providing face detection features. See DetectionOptions in FaceDetector documentation for details.

`flashMode`

Optional • Type: number | FlashMode • Default: FlashMode.off

Camera flash mode. Use one of FlashMode.<value>. When FlashMode.on, the flash on your device will turn on when taking a picture, when FlashMode.off, it won't. Setting to FlashMode.auto will fire flash if required, FlashMode.torch turns on flash during the preview.

`focusDepth`

Optional • Type: number • Default: 0

Distance to plane of the sharpest focus. A value between 0 and 1 where: 0 - infinity focus, 1 - focus as close as possible. For Android this is available only for some devices and when useCamera2Api is set to true.

`pictureSize`

Optional • Type: string

A string representing the size of pictures takePictureAsync will take. Available sizes can be fetched with getAvailablePictureSizesAsync.

Only for:

Web

`poster`

Optional • Type: string

A URL for an image to be shown while the camera is loading.

Only for:

Android

`ratio`

Optional • Type: string • Default: 4:3

A string representing aspect ratio of the preview, eg. 4:3, 16:9, 1:1. To check if a ratio is supported by the device use getSupportedRatiosAsync.

`type`

Optional • Type: number | CameraType • Default: CameraType.back

Camera facing. Use one of CameraType. When CameraType.front, use the front-facing camera. When CameraType.back, use the back-facing camera.

Only for:

Android

`useCamera2Api`

Optional • Type: boolean

Whether to use Android's Camera2 API. See Note at the top of this page.

Only for:

iOS

`videoStabilizationMode`

Optional • Type: number

The video stabilization mode used for a video recording. Use one of VideoStabilization.<value>. You can read more about each stabilization type in Apple Documentation.

`whiteBalance`

Optional • Type: number | WhiteBalance • Default: WhiteBalance.auto

Camera white balance. Use one of WhiteBalance.<value>. If a device does not support any of these values previous one is used.

`zoom`

Optional • Type: number • Default: 0

A value between 0 and 1 being a percentage of device's max zoom. 0 - not zoomed, 1 - maximum zoom.

`onBarCodeScanned`

Optional • Type: (scanningResult: BarCodeScanningResult) => void

Callback that is invoked when a bar code has been successfully scanned. The callback is provided with an object of the BarCodeScanningResult shape, where the type refers to the bar code type that was scanned and the data is the information encoded in the bar code (in this case of QR codes, this is often a URL). See BarCodeScanner.Constants.BarCodeType for supported values.

`onCameraReady`

Optional • Type: () => void

Callback invoked when camera preview has been set.

`onFacesDetected`

Optional • Type: (faces: FaceDetectionResult) => void

Callback invoked with results of face detection on the preview. See FaceDetector documentation for details.

`onMountError`

Optional • Type: (event: CameraMountError) => void

Callback invoked when camera preview could not been started.

Inherited Props

ViewProps

Static Methods

Only for:

Web

`getAvailableCameraTypesAsync()`

Returns a list of camera types ['front', 'back']. This is useful for desktop browsers which only have front-facing cameras.

Name	Type	Description
canAskAgain	`boolean`	Indicates if user can be asked again for specific permission. If not, one should be directed to the Settings app in order to enable/disable the permission.
expires	`PermissionExpiration`	Determines time when the permission expires.
granted	`boolean`	A convenience boolean that indicates if the permission is granted.
status	`PermissionStatus`	Determines the status of the permission.

Name	Type	Description
bounds	`BarCodeBounds`	The BarCodeBounds object. `bounds` in some case will be representing an empty rectangle. Moreover, `bounds` doesn't have to bound the whole barcode. For some types, they will represent the area used by the scanner.
cornerPoints	`BarCodePoint[]`	Corner points of the bounding box. `cornerPoints` is not always available and may be empty. On iOS, for `code39` and `pdf417` you don't get this value.
data	`string`	The information encoded in the bar code.
type	`string`	The barcode type.

Name	Type	Description
base64 (optional)	`string`	-
exif (optional)	`Partial<MediaTrackSettings> \| any`	-
height	`number`	-
uri	`string`	-
width	`number`	-

Name	Type	Description
additionalExif (optional)	`undefined`	Only for: Android iOS Additional EXIF data to be included for the image. Only useful when `exif` option is set to `true`.
base64 (optional)	`boolean`	Whether to also include the image data in Base64 format.
exif (optional)	`boolean`	Whether to also include the EXIF data for the image.
imageType (optional)	`ImageType`	-
isImageMirror (optional)	`boolean`	-
quality (optional)	`number`	Specify the quality of compression, from 0 to 1. 0 means compress for small size, 1 means compress for maximum quality.
scale (optional)	`number`	-
skipProcessing (optional)	`boolean`	If set to `true`, camera skips orientation adjustment and returns an image straight from the device's camera. If enabled, `quality` option is discarded (processing pipeline is skipped as a whole). Although enabling this option reduces image delivery time significantly, it may cause the image to appear in a wrong orientation in the `Image` component (at the time of writing, it does not respect EXIF orientation of the images). Note: Enabling `skipProcessing` would cause orientation uncertainty. `Image` component does not respect EXIF stored orientation information, that means obtained image would be displayed wrongly (rotated by 90°, 180° or 270°). Different devices provide different orientations. For example some Sony Xperia or Samsung devices don't provide correctly oriented images by default. To always obtain correctly oriented image disable `skipProcessing` option.
onPictureSaved (optional)	`(picture: CameraCapturedPicture) => void`	A callback invoked when picture is saved. If set, the promise of this method will resolve immediately with no data after picture is captured. The data that it should contain will be passed to this callback. If displaying or processing a captured photo right after taking it is not your case, this callback lets you skip waiting for it to be saved.

Name	Type	Description
codec (optional)	`VideoCodec`	Only for: iOS This option specifies what codec to use when recording the video. See `VideoCodec` for the possible values.
maxDuration (optional)	`number`	Maximum video duration in seconds.
maxFileSize (optional)	`number`	Maximum video file size in bytes.
mirror (optional)	`boolean`	Only for: iOS If `true`, the recorded video will be flipped along the vertical axis. iOS flips videos recorded with the front camera by default, but you can reverse that back by setting this to `true`. On Android, this is handled in the user's device settings.
mute (optional)	`boolean`	If present, video will be recorded with no sound.
quality (optional)	`number \| string`	Specify the quality of recorded video. Use one of `VideoQuality.<value>`. Possible values: for 16:9 resolution `2160p`, `1080p`, `720p`, `480p` : `Android only` and for 4:3 `4:3` (the size is 640x480). If the chosen quality is not available for a device, the highest available is chosen.
videoBitrate (optional)	`number`	Only for: Android Only works if `useCamera2Api` is set to `true`. This option specifies a desired video bitrate. For example, `510001000` would be 5Mbps.

Name	Type	Description
AutoFocus	`AutoFocus`	-
FlashMode	`FlashMode`	-
Type	`CameraType`	-
VideoCodec	`VideoCodec`	-
VideoQuality	`VideoQuality`	-
VideoStabilization	`VideoStabilization`	-
WhiteBalance	`WhiteBalance`	-