Detect the file type of a Buffer/Uint8Array/ArrayBuffer
The file type is detected by checking the magic number of the buffer.
This package is for detecting binary-based file formats, not text-based formats like .txt
, .csv
, .svg
, etc.
My open source work is supported by the community
Special thanks to:npm install file-type
Determine file type from a file:
import {fileTypeFromFile} from 'file-type';
console.log(await fileTypeFromFile('Unicorn.png'));
//=> {ext: 'png', mime: 'image/png'}
Determine file type from a Buffer, which may be a portion of the beginning of a file:
import {fileTypeFromBuffer} from 'file-type';
import {readChunk} from 'read-chunk';
const buffer = await readChunk('Unicorn.png', {length: 4100});
console.log(await fileTypeFromBuffer(buffer));
//=> {ext: 'png', mime: 'image/png'}
Determine file type from a stream:
import fs from 'node:fs';
import {fileTypeFromStream} from 'file-type';
const stream = fs.createReadStream('Unicorn.mp4');
console.log(await fileTypeFromStream(stream));
//=> {ext: 'mp4', mime: 'video/mp4'}
The stream method can also be used to read from a remote location:
import got from 'got';
import {fileTypeFromStream} from 'file-type';
const url = 'https://upload.wikimedia.org/wikipedia/en/a/a9/Example.jpg';
const stream = got.stream(url);
console.log(await fileTypeFromStream(stream));
//=> {ext: 'jpg', mime: 'image/jpeg'}
Another stream example:
import stream from 'node:stream';
import fs from 'node:fs';
import crypto from 'node:crypto';
import {fileTypeStream} from 'file-type';
const read = fs.createReadStream('encrypted.enc');
const decipher = crypto.createDecipheriv(alg, key, iv);
const streamWithFileType = await fileTypeStream(stream.pipeline(read, decipher));
console.log(streamWithFileType.fileType);
//=> {ext: 'mov', mime: 'video/quicktime'}
const write = fs.createWriteStream(`decrypted.${streamWithFileType.fileType.ext}`);
streamWithFileType.pipe(write);
import {fileTypeFromStream} from 'file-type';
const url = 'https://upload.wikimedia.org/wikipedia/en/a/a9/Example.jpg';
const response = await fetch(url);
const fileType = await fileTypeFromStream(response.body);
console.log(fileType);
//=> {ext: 'jpg', mime: 'image/jpeg'}
import {fileTypeFromBlob} from 'file-type';
const blob = new Blob(['<?xml version="1.0" encoding="ISO-8859-1" ?>'], {
type: 'plain/text',
endings: 'native'
});
console.log(await fileTypeFromBlob(blob));
//=> {ext: 'txt', mime: 'plain/text'}
Detect the file type of a Buffer
, Uint8Array
, or ArrayBuffer
.
The file type is detected by checking the magic number of the buffer.
If file access is available, it is recommended to use FileType.fromFile()
instead.
Returns a Promise
for an object with the detected file type and MIME type:
ext
- One of the supported file typesmime
- The MIME type
Or undefined
when there is no match.
Type: Buffer | Uint8Array | ArrayBuffer
A buffer representing file data. It works best if the buffer contains the entire file, it may work with a smaller portion as well.
Detect the file type of a file path.
The file type is detected by checking the magic number of the buffer.
Returns a Promise
for an object with the detected file type and MIME type:
ext
- One of the supported file typesmime
- The MIME type
Or undefined
when there is no match.
Type: string
The file path to parse.
Detect the file type of a Node.js readable stream.
The file type is detected by checking the magic number of the buffer.
Returns a Promise
for an object with the detected file type and MIME type:
ext
- One of the supported file typesmime
- The MIME type
Or undefined
when there is no match.
Type: stream.Readable
A readable stream representing file data.
Detect the file type from an ITokenizer
source.
This method is used internally, but can also be used for a special "tokenizer" reader.
A tokenizer propagates the internal read functions, allowing alternative transport mechanisms, to access files, to be implemented and used.
Returns a Promise
for an object with the detected file type and MIME type:
ext
- One of the supported file typesmime
- The MIME type
Or undefined
when there is no match.
An example is @tokenizer/http
, which requests data using HTTP-range-requests. A difference with a conventional stream and the tokenizer, is that it can ignore (seek, fast-forward) in the stream. For example, you may only need and read the first 6 bytes, and the last 128 bytes, which may be an advantage in case reading the entire file would take longer.
import {makeTokenizer} from '@tokenizer/http';
import {fileTypeFromTokenizer} from 'file-type';
const audioTrackUrl = 'https://test-audio.netlify.com/Various%20Artists%20-%202009%20-%20netBloc%20Vol%2024_%20tiuqottigeloot%20%5BMP3-V2%5D/01%20-%20Diablo%20Swing%20Orchestra%20-%20Heroines.mp3';
const httpTokenizer = await makeTokenizer(audioTrackUrl);
const fileType = await fileTypeFromTokenizer(httpTokenizer);
console.log(fileType);
//=> {ext: 'mp3', mime: 'audio/mpeg'}
Or use @tokenizer/s3
to determine the file type of a file stored on Amazon S3:
import S3 from 'aws-sdk/clients/s3';
import {makeTokenizer} from '@tokenizer/s3';
import {fileTypeFromTokenizer} from 'file-type';
// Initialize the S3 client
const s3 = new S3();
// Initialize the S3 tokenizer.
const s3Tokenizer = await makeTokenizer(s3, {
Bucket: 'affectlab',
Key: '1min_35sec.mp4'
});
// Figure out what kind of file it is.
const fileType = await fileTypeFromTokenizer(s3Tokenizer);
console.log(fileType);
Note that only the minimum amount of data required to determine the file type is read (okay, just a bit extra to prevent too many fragmented reads).
Type: ITokenizer
A file source implementing the tokenizer interface.
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.fromFile()
.
This method can be handy to put in between a stream, but it comes with a price.
Internally stream()
builds up a buffer of sampleSize
bytes, used as a sample, to determine the file type.
The sample size impacts the file detection resolution.
A smaller sample size will result in lower probability of the best file type detection.
Note: This method is only available when using Node.js. Note: Requires Node.js 14 or later.
Type: stream.Readable
Type: object
Type: number
Default: 4100
The sample size in bytes.
import got from 'got';
import {fileTypeStream} from 'file-type';
const url = 'https://upload.wikimedia.org/wikipedia/en/a/a9/Example.jpg';
const stream1 = got.stream(url);
const stream2 = await fileTypeStream(stream1, {sampleSize: 1024});
if (stream2.fileType && stream2.fileType.mime === 'image/jpeg') {
// stream2 can be used to stream the JPEG image (from the very beginning of the stream)
}
Type: stream.Readable
The input stream.
Returns a Set<string>
of supported file extensions.
Returns a Set<string>
of supported MIME types.
jpg
- Joint Photographic Experts Group imagepng
- Portable Network Graphicsapng
- Animated Portable Network Graphicsgif
- Graphics Interchange Formatwebp
- Web Picture formatflif
- Free Lossless Image Formatxcf
- eXperimental Computing Facilitycr2
- 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 filetif
- Tagged Image filebmp
- Bitmap image fileicns
- Apple Icon imagejxr
- Joint Photographic Experts Group extended rangepsd
- Adobe Photoshop documentindd
- Adobe InDesign documentzip
- Archive filetar
- Tarball archive filerar
- Archive filegz
- Archive filebz2
- Archive filezst
- Archive file7z
- 7-Zip archivedmg
- Apple Disk Imagemp4
- MPEG-4 Part 14 video filemid
- Musical Instrument Digital Interface filemkv
- Matroska video filewebm
- Web video filemov
- QuickTime video fileavi
- Audio Video Interleave filempg
- MPEG-1 filemp1
- MPEG-1 Audio Layer Imp2
- MPEG-1 Audio Layer IImp3
- Audio fileogg
- Audio fileogv
- Audio fileogm
- Audio fileoga
- Audio filespx
- Audio fileogx
- Audio fileopus
- Audio fileflac
- Free Lossless Audio Codecwav
- Waveform Audio fileqcp
- Tagged and chunked dataamr
- Adaptive Multi-Rate audio codecpdf
- Portable Document Formatepub
- E-book filemobi
- Mobipocketelf
- Unix Executable and Linkable Formatexe
- Executable fileswf
- Adobe Flash Player filertf
- Rich Text Formatwoff
- Web Open Font Formatwoff2
- Web Open Font Formateot
- Embedded OpenType fontttf
- TrueType fontotf
- OpenType fontico
- Windows icon fileflv
- Flash videops
- Postscriptxz
- Compressed filesqlite
- SQLite filenes
- Nintendo NES ROMcrx
- Google Chrome extensionxpi
- XPInstall filecab
- Cabinet filedeb
- Debian packagear
- Archive filerpm
- Red Hat Package Manager fileZ
- Unix Compressed Filelz
- Arhive filecfb
- Compount File Binary Formatmxf
- Material Exchange Formatmts
- MPEG-2 Transport Stream, both raw and Blu-ray Disc Audio-Video (BDAV) versionswasm
- WebAssembly intermediate compiled formatblend
- Blender projectbpg
- Better Portable Graphics filedocx
- Microsoft Wordpptx
- Microsoft Powerpointxlsx
- Microsoft Exceljp2
- JPEG 2000jpm
- JPEG 2000jpx
- JPEG 2000mj2
- Motion JPEG 2000aif
- Audio Interchange fileodt
- OpenDocument for word processingods
- OpenDocument for spreadsheetsodp
- OpenDocument for presentationsxml
- eXtensible Markup Languageheic
- High Efficiency Image File Formatcur
- Icon filektx
- OpenGL and OpenGL ES texturesape
- Monkey's Audiowv
- WavPackasf
- Advanced Systems Formatdcm
- DICOM Image Filempc
- Musepack (SV7 & SV8)ics
- iCalendarvcf
- vCardglb
- 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 dataaac
- Advanced Audio Codingit
- Audio module format: Impulse Trackers3m
- Audio module format: ScreamTracker 3xm
- Audio module format: FastTracker 2ai
- Adobe Illustrator Artworkskp
- SketchUpavif
- AV1 Image File Formateps
- Encapsulated PostScriptlzh
- LZH archivepgp
- Pretty Good Privacyasar
- Archive format primarily used to enclose Electron applicationsstl
- Standard Tesselated Geometry File Format (ASCII only)chm
- Microsoft Compiled HTML Help3mf
- 3D Manufacturing Formatjxl
- JPEG XL image format
Pull requests are welcome for additional commonly used file types.
The following file types will not be accepted:
- MS-CFB: Microsoft Compound File Binary File Format based formats, too old and difficult to parse:
.doc
- Microsoft Word 97-2003 Document.xls
- Microsoft Excel 97-2003 Document.ppt
- Microsoft PowerPoint97-2003 Document.msi
- Microsoft Windows Installer
.csv
- Reason..svg
- Detecting it requires a full-blown parser. Check outis-svg
for something that mostly works.
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- file-type-cli - CLI for this module