Detect the file type of a Buffer/Uint8Array/ArrayBuffer
The file type is detected by checking the magic number of the buffer.
$ npm install file-type
const readChunk = require('read-chunk');
const fileType = require('file-type');
const buffer = readChunk.sync('unicorn.png', 0, fileType.minimumBytes);
fileType(buffer);
//=> {ext: 'png', mime: 'image/png'}Or from a remote location:
const https = require('https');
const fileType = require('file-type');
const url = 'https://upload.wikimedia.org/wikipedia/en/a/a9/Example.jpg';
https.get(url, response => {
response.on('readable', () => {
const chunk = response.read(fileType.minimumBytes);
response.destroy();
console.log(fileType(chunk));
//=> {ext: 'jpg', mime: 'image/jpeg'}
});
});Or from a stream:
const stream = require('stream');
const fs = require('fs');
const crypto = require('crypto');
const fileType = require('file-type');
(async () => {
const read = fs.createReadStream('encrypted.enc');
const decipher = crypto.createDecipheriv(alg, key, iv);
const fileTypeStream = await fileType.stream(stream.pipeline(read, decipher));
console.log(fileTypeStream.fileType);
//=> {ext: 'mov', mime: 'video/quicktime'}
const write = fs.createWriteStream(`decrypted.${fileTypeStream.fileType.ext}`);
fileTypeStream.pipe(write);
})();const xhr = new XMLHttpRequest();
xhr.open('GET', 'unicorn.png');
xhr.responseType = 'arraybuffer';
xhr.onload = () => {
fileType(new Uint8Array(this.response));
//=> {ext: 'png', mime: 'image/png'}
};
xhr.send();Returns an object with:
ext- One of the supported file typesmime- The MIME type
Or undefined when there is no match.
Type: Buffer | Uint8Array | ArrayBuffer
It only needs the first .minimumBytes bytes. The exception is detection of docx, pptx, and xlsx which potentially requires reading the whole file.
Type: number
The minimum amount of bytes needed to detect a file type. Currently, it's 4100 bytes, but it can change, so don't hardcode it.
Detect the file type of a readable stream.
Returns a Promise which resolves to the original readable stream argument, but with an added fileType property, which is an object like the one returned from fileType().
Note: This method is only for Node.js.
Type: stream.Readable
Returns a set of supported file extensions.
Returns a set of supported MIME types.
jpgpngapng- Animated Portable Network Graphicsgifwebpflifcr2- Canon Raw image file (v2)cr3- Canon Raw image file (v3)orf- Olympus Raw image filearw- Sony Alpha Raw image filedng- Adobe Digital Negative image filenef- Nikon Electronic Format image filerw2- Panasonic RAW image fileraf- Fujifilm RAW image filetifbmpjxrpsdziptarrargzbz27zdmgmp4midmkvwebmmovavimpgmp2mp3oggogvogmogaspxogxopusflacwavqcpamrpdfepubmobi- Mobipocketexeswfrtfwoffwoff2eotttfotficoflvpsxzsqlitenescrxxpicabdebarrpmZlzmsimxfmtswasmblendbpgdocxpptxxlsxjp2- JPEG 2000jpm- JPEG 2000jpx- JPEG 2000mj2- Motion JPEG 2000aifodt- OpenDocument for word processingods- OpenDocument for spreadsheetsodp- OpenDocument for presentationsxmlheiccurktxape- Monkey's Audiowv- WavPackasf- Advanced Systems Formatwma- Windows Media Audiowmv- Windows Media Videodcm- DICOM Image Filempc- Musepack (SV7 & SV8)ics- iCalendarglb- GL Transmission Formatpcap- Libpcap File Formatdsf- Sony DSD Stream File (DSF)lnk- Microsoft Windows file shortcutalias- macOS Alias filevoc- Creative Voice Fileac3- ATSC A/52 Audio File3gp- Multimedia container format defined by the Third Generation Partnership Project (3GPP) for 3G UMTS multimedia services3g2- Multimedia container format defined by the 3GPP2 for 3G CDMA2000 multimedia servicesm4v- MPEG-4 Visual bitstreamsm4p- MPEG-4 files with audio streams encrypted by FairPlay Digital Rights Management as were sold through the iTunes Storem4a- Audio-only MPEG-4 filesm4b- Audiobook and podcast MPEG-4 files, which also contain metadata including chapter markers, images, and hyperlinksf4v- ISO base media file format used by Adobe Flash Playerf4p- ISO base media file format protected by Adobe Access DRM used by Adobe Flash Playerf4a- Audio-only ISO base media file format used by Adobe Flash Playerf4b- Audiobook and podcast ISO base media file format used by Adobe Flash Playermie- Dedicated meta information format which supports storage of binary as well as textual meta informationshp- Geospatial vector data formatarrow- Columnar format for tables of data
SVG isn't included as it requires the whole file to be read, but you can get it here.
Pull requests are welcome for additional commonly used file types, except for doc, xls, ppt.
Available as part of the Tidelift Subscription.
The maintainers of file-type and thousands of other packages are working with Tidelift to deliver commercial support and maintenance for the open source dependencies you use to build your applications. Save time, reduce risk, and improve code health, while paying the maintainers of the exact dependencies you use. Learn more.
- file-type-cli - CLI for this module