Gathering detailed insights and metrics for file-type
path-type
Check if a path is a file, directory, or symlink
mime
A comprehensive library for mime-type mapping
@atlaskit/icon-file-type
A file type icon is used to represent specific types of content used across Atlassian products.
filepond-plugin-file-validate-type
File Type Validation Plugin for FilePond
Detect the file type of a file, stream, or data
npm install file-typeTypescript
Module System
Min. Node Version
Node Version
NPM Version
98.9
Supply Chain
98.3
Quality
87.8
Maintenance
100
Vulnerability
100
License
JavaScript (75.08%)
PostScript (22.85%)
TypeScript (1.75%)
Rich Text Format (0.33%)
Total Downloads
5,510,874,589
Last Day
3,361,633
Last Week
20,400,174
Last Month
67,166,301
Last Year
1,046,902,239
3,831 Stars
558 Commits
373 Forks
30 Watching
9 Branches
107 Contributors
Minified
Minified + Gzipped
Latest Version
20.0.0
Package Id
file-type@20.0.0
Unpacked Size
99.91 kB
Size
24.55 kB
File Count
9
NPM Version
10.9.0
Node Version
23.3.0
Publised On
15 Jan 2025
Cumulative downloads
Total Downloads
Last day
-5.6%
3,361,633
Compared to previous day
Last week
4%
20,400,174
Compared to previous week
Last month
-24.7%
67,166,301
Compared to previous month
Last year
1.1%
1,046,902,239
Compared to previous year
8
Detect the file type of a file, stream, or data
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.
We accept contributions for commonly used modern file formats, not historical or obscure ones. Open an issue first for discussion.
1npm install file-type
This package is an ESM package. Your project needs to be ESM too. Read more. For TypeScript + CommonJS, see load-esm.
If you use it with Webpack, you need the latest Webpack version and ensure you configure it correctly for ESM.
Determine file type from a file:
1import {fileTypeFromFile} from 'file-type'; 2 3console.log(await fileTypeFromFile('Unicorn.png')); 4//=> {ext: 'png', mime: 'image/png'}
Determine file type from a Uint8Array/ArrayBuffer, which may be a portion of the beginning of a file:
1import {fileTypeFromBuffer} from 'file-type'; 2import {readChunk} from 'read-chunk'; 3 4const buffer = await readChunk('Unicorn.png', {length: 4100}); 5 6console.log(await fileTypeFromBuffer(buffer)); 7//=> {ext: 'png', mime: 'image/png'}
Determine file type from a stream:
1import fs from 'node:fs'; 2import {fileTypeFromStream} from 'file-type'; 3 4const stream = fs.createReadStream('Unicorn.mp4'); 5 6console.log(await fileTypeFromStream(stream)); 7//=> {ext: 'mp4', mime: 'video/mp4'}
The stream method can also be used to read from a remote location:
1import got from 'got'; 2import {fileTypeFromStream} from 'file-type'; 3 4const url = 'https://upload.wikimedia.org/wikipedia/en/a/a9/Example.jpg'; 5 6const stream = got.stream(url); 7 8console.log(await fileTypeFromStream(stream)); 9//=> {ext: 'jpg', mime: 'image/jpeg'}
Another stream example:
1import stream from 'node:stream'; 2import fs from 'node:fs'; 3import crypto from 'node:crypto'; 4import {fileTypeStream} from 'file-type'; 5 6const read = fs.createReadStream('encrypted.enc'); 7const decipher = crypto.createDecipheriv(alg, key, iv); 8 9const streamWithFileType = await fileTypeStream(stream.pipeline(read, decipher)); 10 11console.log(streamWithFileType.fileType); 12//=> {ext: 'mov', mime: 'video/quicktime'} 13 14const write = fs.createWriteStream(`decrypted.${streamWithFileType.fileType.ext}`); 15streamWithFileType.pipe(write);
1import {fileTypeFromStream} from 'file-type'; 2 3const url = 'https://upload.wikimedia.org/wikipedia/en/a/a9/Example.jpg'; 4 5const response = await fetch(url); 6const fileType = await fileTypeFromStream(response.body); 7 8console.log(fileType); 9//=> {ext: 'jpg', mime: 'image/jpeg'}
Detect the file type of a 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 fileTypeFromFile() instead.
Returns a Promise for an object with the detected file type:
ext - One of the supported file typesmime - The MIME typeOr undefined when there is no match.
Type: 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.
This is for Node.js only.
To read from a File, see fileTypeFromBlob().
The file type is detected by checking the magic number of the buffer.
Returns a Promise for an object with the detected file type:
ext - One of the supported file typesmime - The MIME typeOr undefined when there is no match.
Type: string
The file path to parse.
Detect the file type of a web ReadableStream.
If the engine is Node.js, this may also be a Node.js stream.Readable.
Direct support for Node.js streams will be dropped in the future, when Node.js streams can be converted to Web streams (see toWeb()).
The file type is detected by checking the magic number of the buffer.
Returns a Promise for an object with the detected file type:
ext - One of the supported file typesmime - The MIME typeOr undefined when there is no match.
Type: Web ReadableStream or Node.js stream.Readable
A readable stream representing file data.
Detect the file type of a Blob,
[!TIP] A
Fileobject is aBloband can be passed in here.
It will stream the underlying Blob.
The file type is detected by checking the magic number of the blob.
Returns a Promise for an object with the detected file type:
ext - One of the supported file typesmime - The MIME typeOr undefined when there is no match.
1import {fileTypeFromBlob} from 'file-type'; 2 3const blob = new Blob(['<?xml version="1.0" encoding="ISO-8859-1" ?>'], { 4 type: 'text/plain', 5 endings: 'native' 6}); 7 8console.log(await fileTypeFromBlob(blob)); 9//=> {ext: 'txt', mime: 'text/plain'}
[!WARNING] This method depends on ReadableStreamBYOBReader which requires Node.js ≥ 20 and may not be available in all modern browsers.
To work around this limitation, you can use an alternative approach to read and process the Blob without relying on streaming:
1import {fileTypeFromBuffer} from 'file-type'; 2 3async function readFromBlobWithoutStreaming(blob) { 4 const buffer = await blob.arrayBuffer(); 5 return fileTypeFromBuffer(buffer); 6}
Type: Blob
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:
ext - One of the supported file typesmime - The MIME typeOr 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.
1import {makeTokenizer} from '@tokenizer/http'; 2import {fileTypeFromTokenizer} from 'file-type'; 3 4const 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'; 5 6const httpTokenizer = await makeTokenizer(audioTrackUrl); 7const fileType = await fileTypeFromTokenizer(httpTokenizer); 8 9console.log(fileType); 10//=> {ext: 'mp3', mime: 'audio/mpeg'}
Or use @tokenizer/s3 to determine the file type of a file stored on Amazon S3:
1import S3 from 'aws-sdk/clients/s3'; 2import {makeTokenizer} from '@tokenizer/s3'; 3import {fileTypeFromTokenizer} from 'file-type'; 4 5// Initialize the S3 client 6const s3 = new S3(); 7 8// Initialize the S3 tokenizer. 9const s3Tokenizer = await makeTokenizer(s3, { 10 Bucket: 'affectlab', 11 Key: '1min_35sec.mp4' 12}); 13 14// Figure out what kind of file it is. 15const fileType = await fileTypeFromTokenizer(s3Tokenizer); 16console.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 fileTypeFromFile().
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: When using Node.js, a stream.Readable may be provided as well.
Type: stream.Readable
Type: object
Type: number
Default: 4100
The sample size in bytes.
1import got from 'got'; 2import {fileTypeStream} from 'file-type'; 3 4const url = 'https://upload.wikimedia.org/wikipedia/en/a/a9/Example.jpg'; 5 6const stream1 = got.stream(url); 7const stream2 = await fileTypeStream(stream1, {sampleSize: 1024}); 8 9if (stream2.fileType?.mime === 'image/jpeg') { 10 // stream2 can be used to stream the JPEG image (from the very beginning of the stream) 11}
Type: stream.Readable
The input stream.
Returns a Set<string> of supported file extensions.
Returns a Set<string> of supported MIME types.
A custom file type detector.
Detectors can be added via the constructor options or by directly modifying FileTypeParser#detectors.
Detectors provided through the constructor options are executed before the default detectors.
Custom detectors allow for:
FileTypeResult entries.FileTypeResult types.If a detector returns undefined, the following rules apply:
tokenizer.position is advanced), no further detectors are executed. In this case, the file type remains undefined, as subsequent detectors cannot evaluate the content. This is an exceptional scenario, as it prevents any other detectors from determining the file type.Below is an example of a custom detector array. This can be passed to the FileTypeParser via the fileTypeOptions argument.
1import {FileTypeParser} from 'file-type'; 2 3const unicornDetector = { 4 id: 'unicorn', // May be used to recognize the detector in the detector list 5 async detect(tokenizer) { 6 const unicornHeader = [85, 78, 73, 67, 79, 82, 78]; // "UNICORN" in ASCII decimal 7 8 const buffer = new Uint8Array(unicornHeader.length); 9 await tokenizer.peekBuffer(buffer, {length: unicornHeader.length, mayBeLess: true}); 10 if (unicornHeader.every((value, index) => value === buffer[index])) { 11 return {ext: 'unicorn', mime: 'application/unicorn'}; 12 } 13 14 return undefined; 15 } 16} 17 18const buffer = new Uint8Array([85, 78, 73, 67, 79, 82, 78]); 19const parser = new FileTypeParser({customDetectors: [unicornDetector]}); 20const fileType = await parser.fromBuffer(buffer); 21console.log(fileType); // {ext: 'unicorn', mime: 'application/unicorn'}
1/** 2@param tokenizer - The [tokenizer](https://github.com/Borewit/strtok3#tokenizer) used to read file content. 3@param fileType - The file type detected by standard or previous custom detectors, or `undefined` if no match is found. 4@returns The detected file type, or `undefined` if no match is found. 5*/ 6export type Detector = (tokenizer: ITokenizer, fileType?: FileTypeResult) => Promise<FileTypeResult | undefined>;
Some async operations can be aborted by passing an AbortSignal to the FileTypeParser constructor.
1import {FileTypeParser} from 'file-type';
2
3const abortController = new AbortController()
4
5const parser = new FileTypeParser({abortSignal: abortController.signal});
6
7const promise = parser.fromStream(blob.stream());
8
9abortController.abort(); // Abort file-type reading from the Blob stream.3g2 - Multimedia container format defined by the 3GPP2 for 3G CDMA2000 multimedia services3gp - Multimedia container format defined by the Third Generation Partnership Project (3GPP) for 3G UMTS multimedia services3mf - 3D Manufacturing Format7z - 7-Zip archiveZ - Unix Compressed Fileaac - Advanced Audio Codingac3 - ATSC A/52 Audio Fileace - ACE archiveai - Adobe Illustrator Artworkaif - Audio Interchange filealias - macOS Alias fileamr - Adaptive Multi-Rate audio codecape - Monkey's Audioapk - Android package formatapng - Animated Portable Network Graphicsar - Archive filearj - Archive filearrow - Columnar format for tables of dataarw - Sony Alpha Raw image fileasar - Archive format primarily used to enclose Electron applicationsasf - Advanced Systems Formatavi - Audio Video Interleave fileavif - AV1 Image File Formatavro - Object container file developed by Apache Avroblend - Blender projectbmp - Bitmap image filebpg - Better Portable Graphics filebz2 - Archive filecab - Cabinet filecfb - Compound File Binary Formatchm - Microsoft Compiled HTML Helpclass - Java class filecpio - Cpio archivecr2 - Canon Raw image file (v2)cr3 - Canon Raw image file (v3)crx - Google Chrome extensioncur - Icon filedcm - DICOM Image Filedeb - Debian packagedmg - Apple Disk Imagedng - Adobe Digital Negative image filedocm - Microsoft Word macro-enabled documentdocx - Microsoft Word documentdotm - Microsoft Word macro-enabled templatedotx - Microsoft Word templatedrc - Google's Draco 3D Data Compressiondsf - Sony DSD Stream File (DSF)dwg - Autodesk CAD fileelf - Unix Executable and Linkable Formateot - Embedded OpenType fonteps - Encapsulated PostScriptepub - E-book fileexe - Executable filef4a - Audio-only ISO base media file format used by Adobe Flash Playerf4b - Audiobook and podcast ISO base media file format used by Adobe Flash Playerf4p - ISO base media file format protected by Adobe Access DRM used by Adobe Flash Playerf4v - ISO base media file format used by Adobe Flash Playerfbx - Filmbox is a proprietary file format used to provide interoperability between digital content creation apps.flac - Free Lossless Audio Codecflif - Free Lossless Image Formatflv - Flash videogif - Graphics Interchange Formatglb - GL Transmission Formatgz - Archive fileheic - High Efficiency Image File Formaticc - ICC Profileicns - Apple Icon imageico - Windows icon fileics - iCalendarindd - Adobe InDesign documentit - Audio module format: Impulse Trackerj2c - JPEG 2000jar - Java archivejls - Lossless/near-lossless compression standard for continuous-tone imagesjp2 - JPEG 2000jpg - Joint Photographic Experts Group imagejpm - JPEG 2000jpx - JPEG 2000jxl - JPEG XL image formatjxr - Joint Photographic Experts Group extended rangektx - OpenGL and OpenGL ES textureslnk - Microsoft Windows file shortcutlz - Archive filelz4 - Compressed archive created by one of a variety of LZ4 compression utilitieslzh - LZH archivem4a - Audio-only MPEG-4 filesm4b - Audiobook and podcast MPEG-4 files, which also contain metadata including chapter markers, images, and hyperlinksm4p - MPEG-4 files with audio streams encrypted by FairPlay Digital Rights Management as were sold through the iTunes Storem4v - Video container format developed by Apple, which is very similar to the MP4 formatmacho - Mach-O binary formatmid - Musical Instrument Digital Interface filemie - Dedicated meta information format which supports storage of binary as well as textual meta informationmj2 - Motion JPEG 2000mkv - Matroska video filemobi - Mobipocketmov - QuickTime video filemp1 - MPEG-1 Audio Layer Imp2 - MPEG-1 Audio Layer IImp3 - Audio filemp4 - MPEG-4 Part 14 video filempc - Musepack (SV7 & SV8)mpg - MPEG-1 filemts - MPEG-2 Transport Stream, both raw and Blu-ray Disc Audio-Video (BDAV) versionsmxf - Material Exchange Formatnef - Nikon Electronic Format image filenes - Nintendo NES ROModg - OpenDocument for drawingodp - OpenDocument for presentationsods - OpenDocument for spreadsheetsodt - OpenDocument for word processingoga - Audio fileogg - Audio fileogm - Audio fileogv - Audio fileogx - Audio fileopus - Audio fileorf - Olympus Raw image fileotf - OpenType fontotg - OpenDocument template for drawingotp - OpenDocument template for presentationsots - OpenDocument template for spreadsheetsott - OpenDocument template for word processingparquet - Apache Parquetpcap - Libpcap File Formatpdf - Portable Document Formatpgp - Pretty Good Privacypng - Portable Network Graphicspotm - Microsoft PowerPoint macro-enabled templatepotx - Microsoft PowerPoint templatepptm - Microsoft PowerPoint macro-enabled documentpptx - Microsoft PowerPoint documentps - Postscriptpsd - Adobe Photoshop documentpst - Personal Storage Table fileqcp - Tagged and chunked dataraf - Fujifilm RAW image filerar - Archive filerpm - Red Hat Package Manager filertf - Rich Text Formatrw2 - Panasonic RAW image files3m - Audio module format: ScreamTracker 3shp - Geospatial vector data formatskp - SketchUpspx - Audio filesqlite - SQLite filestl - Standard Tesselated Geometry File Format (ASCII only)swf - Adobe Flash Player filetar - Tarball archive filetif - Tagged Image filettf - TrueType fontvcf - vCardvoc - Creative Voice Filevsdx - Microsoft Visio Filevtt - WebVTT File (for video captions)wasm - WebAssembly intermediate compiled formatwav - Waveform Audio filewebm - Web video filewebp - Web Picture formatwoff - Web Open Font Formatwoff2 - Web Open Font Formatwv - WavPackxcf - eXperimental Computing Facilityxlsm - Microsoft Excel macro-enabled documentxlsx - Microsoft Excel documentxltm - Microsoft Excel macro-enabled templatexltx - Microsoft Excel templatexm - Audio module format: FastTracker 2xml - eXtensible Markup Languagexpi - XPInstall filexz - Compressed filezip - Archive filezst - Archive filePull requests are welcome for additional commonly used file types.
The following file types will not be accepted:
.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 out is-svg for something that mostly works.Type: ITokenizer
Usable as source of the examined file.
Type: FileTypeResult
An object having an ext (extension) and mime (mime type) property.
Detected by the standard detections or a previous custom detection. Undefined if no matching fileTypeResult could be found.
Stable Version
2
7.5/10
Summary
file-type vulnerable to Infinite Loop via malformed MKV file
Affected Versions
>= 13.0.0, < 16.5.4
Patched Versions
16.5.4
7.5/10
Summary
file-type vulnerable to Infinite Loop via malformed MKV file
Affected Versions
>= 17.0.0, < 17.1.3
Patched Versions
17.1.3
Reason
security policy file detected
Details
Reason
no dangerous workflow patterns detected
Reason
24 commit(s) and 23 issue activity found in the last 90 days -- score normalized to 10
Reason
0 existing vulnerabilities detected
Reason
license file detected
Details
Reason
Found 26/30 approved changesets -- score normalized to 8
Reason
binaries present in source code
Details
Reason
detected GitHub workflow tokens with excessive permissions
Details
Reason
no effort to earn an OpenSSF best practices badge detected
Reason
project is not fuzzed
Details
Reason
branch protection not enabled on development/release branches
Details
Reason
dependency not pinned by hash detected -- score normalized to 0
Details
Reason
SAST tool is not run on all commits -- score normalized to 0
Details
Score
Last Scanned on 2025-01-13
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