Scan QR codes and barcodes from local image files in React Native (iOS Vision + Android ML Kit), with Expo prebuild support.
- Multi-barcode detection in a single image
- Mixed formats in one scan flow
- Auto preprocessing: grayscale, contrast boost, rotation retry (
0°–270°) - TypeScript support
- React Native
>=0.70.0, React>=17.0.0, Node>=18 - iOS
13.4+, AndroidminSdkVersion 21+
Native module — works with Expo prebuild, not Expo Go.
npx expo install react-native-image-code-scanner
npx expo prebuild --clean
npx expo run:ios # or: npx expo run:androidnpm install react-native-image-code-scanner
cd ios && pod installIf your app picks images from camera, add to Info.plist:
<key>NSCameraUsageDescription</key>
<string>This app needs camera access to scan barcodes</string>Works with any image picker — pass the local file URI to scan():
import * as ImagePicker from 'expo-image-picker';
import ImageCodeScanner, { BarcodeFormat } from 'react-native-image-code-scanner';
async function pickAndScan() {
const picked = await ImagePicker.launchImageLibraryAsync({
mediaTypes: ImagePicker.MediaTypeOptions.Images,
quality: 1,
});
if (picked.canceled || !picked.assets?.[0]?.uri) return [];
const results = await ImageCodeScanner.scan({
path: picked.assets[0].uri,
formats: [BarcodeFormat.QR_CODE, BarcodeFormat.CODE_128],
});
// results is ScanResult[] — may contain 0, 1, or many barcodes
return results;
}Also compatible with react-native-image-picker and other pickers that return a local URI.
ImageCodeScanner.scan(options: ScanOptions): Promise<ScanResult[]>
interface ScanOptions {
path: string;
formats?: BarcodeFormat[]; // default: [QR_CODE]
}
interface ScanResult {
content: string;
format: string; // no bounding-box coordinates
}Multi-barcode: scan() returns all barcodes found in one image — no extra option needed. Preprocessing stops once at least one code is detected, but every code from that pass is returned.
Supported formats: QR_CODE, CODE_128, CODE_39, CODE_93, EAN_13, EAN_8, UPC_A, UPC_E, PDF_417, DATA_MATRIX, AZTEC, ITF, CODABAR
Preprocessing runs automatically: original → grayscale → contrast enhancement → rotation retries.
- Resize very large images before scanning; pass only the
formatsyou need. - Process batch jobs sequentially to reduce memory spikes.
- Test on both iOS and Android for critical flows.
- No result: check image quality/resolution, limit
formats, crop closer to the barcode. - iOS build:
cd ios && pod install; deployment target13.4+. - Android build:
cd android && ./gradlew clean;minSdkVersion >= 21. - Expo: requires prebuild; not supported in Expo Go.
See example app and example README.
Please read CONTRIBUTING.md.
MIT
