File extensions and MIME types

Data last checked 2026-09-20

An extension is the part after the last dot in a file name; it tells the operating system which program to use. The MIME type (media type) is the equivalent label on the web, sent in the Content-Type header and checked by upload forms. The two do not always agree: a portal may refuse a .jpg whose bytes are actually HEIC, and a .ts can be a TypeScript file or a video stream segment. GivenTool checks both the extension and the file's magic bytes for that reason.

The table below covers 120 extensions you are likely to meet in images, video, audio, documents, data, archives, code, fonts and design. MIME types are the IANA-registered ones where a registration exists; where a format has no registration the de-facto type is given and marked. Rows whose format GivenTool can convert or compress link straight to the tool.

Type part of an extension, a format name or a program into the filter to narrow the list.

Extensions, types and MIME types

120 rows

Extension	Type	MIME type	Opens with	Notes	GivenTool tool
.jpg / .jpeg	Image	image/jpeg	Any browser, Photos, Preview	Lossy photo format accepted by every upload form. No transparency.	Compress JPG
.png	Image	image/png	Any browser, Photos, Preview	Lossless with transparency; large for photos, ideal for screenshots and logos.	PNG to JPG
.webp	Image	image/webp	All modern browsers	Google format, 25-35% smaller than JPEG; rejected by many government portals.	WebP to JPG
.heic / .heif	Image	image/heic, image/heif	iPhone, macOS, Windows with codec	Apple's default camera format (HEVC-compressed). Convert to JPG for uploads.	HEIC to JPG
.gif	Image	image/gif	Any browser	256 colours, optional animation. Poor for photos.	Convert GIF
.bmp	Image	image/bmp	Windows Paint, most viewers	Uncompressed Windows bitmap; very large files.	Compress image
.tif / .tiff	Image	image/tiff	Photoshop, Preview, scanners	Lossless, multi-page capable; used by scanners and print. Not shown by most browsers.
.avif	Image	image/avif	Chrome, Firefox, Safari 16+	AV1-based image format, smaller than WebP; limited support outside browsers.	Convert AVIF
.svg	Image (vector)	image/svg+xml	Any browser, Illustrator, Inkscape	XML vector graphics; scales without loss. Can contain scripts, so some uploads reject it.
.ico	Image	image/vnd.microsoft.icon	Browsers (favicons), Windows	Icon container with several sizes.
.psd	Image (layered)	image/vnd.adobe.photoshop	Adobe Photoshop, Affinity, GIMP	Photoshop working file with layers; export to PNG or JPG to share.
.raw / .cr2 / .nef / .arw / .dng	Image (camera raw)	image/x-canon-cr2, image/x-nikon-nef, image/x-adobe-dng	Lightroom, Capture One, camera software	Unprocessed sensor data; DNG is Adobe's open container. Convert to JPG before sharing.
.mp4	Video	video/mp4	Everything	MPEG-4 container, usually H.264 video + AAC audio. The safe choice for uploads.	Compress MP4
.mov	Video	video/quicktime	QuickTime, iPhone, VLC	Apple QuickTime container; often H.264 or HEVC. Convert to MP4 for Windows and web.	MOV to MP4
.m4v	Video	video/x-m4v	Apple devices, VLC	MP4 variant used by iTunes; may carry DRM.	Convert to MP4
.webm	Video	video/webm	Chrome, Firefox, Edge, VLC	Open web container (VP8/VP9/AV1 + Opus/Vorbis). Weak Safari and iOS support.	Convert WebM
.mkv	Video	video/x-matroska	VLC, MPV, Plex	Matroska container holding almost any codec and multiple subtitle tracks; not accepted by most upload forms.	Convert to MP4
.avi	Video	video/x-msvideo	Windows Media Player, VLC	1992 Microsoft container; large files, old codecs.	Convert to MP4
.wmv	Video	video/x-ms-wmv	Windows Media Player, VLC	Windows Media Video; poor support on Apple and web.
.flv	Video	video/x-flv	VLC	Flash Video; obsolete since Flash ended in 2020.
.3gp	Video	video/3gpp	Older phones, VLC	Low-resolution mobile video from feature phones.	Convert to MP4
.mts / .m2ts	Video	video/mp2t	Camcorder software, VLC	AVCHD camcorder recordings (H.264 in MPEG-TS).
.ts	Video	video/mp2t	VLC, streaming players	MPEG transport stream segment used by HLS streaming. Also a TypeScript source file extension.
.mp3	Audio	audio/mpeg	Everything	Universal lossy audio; 128 to 320 kbps.	Convert to MP3
.m4a	Audio	audio/mp4	Apple devices, most players	AAC (or ALAC lossless) in an MP4 container; iPhone Voice Memos.	M4A to MP3
.aac	Audio	audio/aac	Most players	Raw AAC stream; better than MP3 at the same bitrate.	Convert to MP3
.opus	Audio	audio/opus	Browsers, VLC, WhatsApp	WhatsApp and Telegram voice notes; excellent quality at low bitrates.	OPUS to MP3
.ogg / .oga	Audio	audio/ogg	Browsers, VLC	Ogg container with Vorbis or Opus audio.	Convert to MP3
.wav	Audio	audio/wav	Everything	Uncompressed PCM; about 10 MB per minute at CD quality.	WAV to MP3
.flac	Audio	audio/flac	VLC, foobar2000, most phones	Lossless compression, about half the size of WAV.	FLAC to MP3
.wma	Audio	audio/x-ms-wma	Windows Media Player	Windows Media Audio; poor support elsewhere.	Convert to MP3
.amr	Audio	audio/amr	Older phones, VLC	Adaptive Multi-Rate speech codec from older phone recorders.	Convert to MP3
.aiff / .aif	Audio	audio/aiff	macOS, Logic, most players	Apple's uncompressed audio, equivalent to WAV.
.mid / .midi	Audio (notation)	audio/midi	Music software	Instrument instructions, not recorded sound.
.pdf	Document	application/pdf	Any browser, Acrobat, Preview	Fixed-layout document; the standard for forms, scans and official uploads.
.doc	Document	application/msword	Word, LibreOffice, Google Docs	Legacy Word binary format (1997-2003).
.docx	Document	application/vnd.openxmlformats-officedocument.wordprocessingml.document	Word, LibreOffice, Google Docs	Word document (Office Open XML, a ZIP of XML files).
.xls	Spreadsheet	application/vnd.ms-excel	Excel, LibreOffice, Google Sheets	Legacy Excel binary format.
.xlsx	Spreadsheet	application/vnd.openxmlformats-officedocument.spreadsheetml.sheet	Excel, LibreOffice, Google Sheets	Excel workbook (Office Open XML).
.ppt	Presentation	application/vnd.ms-powerpoint	PowerPoint, LibreOffice	Legacy PowerPoint binary format.
.pptx	Presentation	application/vnd.openxmlformats-officedocument.presentationml.presentation	PowerPoint, LibreOffice, Google Slides	PowerPoint presentation (Office Open XML).
.odt / .ods / .odp	Document	application/vnd.oasis.opendocument.text (spreadsheet, presentation)	LibreOffice, OpenOffice, Word	OpenDocument formats, ISO 26300.
.rtf	Document	application/rtf	Word, TextEdit, WordPad	Rich Text Format; simple formatting, wide compatibility.
.txt	Text	text/plain	Any text editor	Plain text with no formatting.
.md	Text	text/markdown	Text editors, GitHub, Obsidian	Markdown: plain text with lightweight formatting marks.
.epub	E-book	application/epub+zip	Apple Books, Kobo, Calibre	Reflowable e-book (ZIP of XHTML).
.mobi / .azw3	E-book	application/x-mobipocket-ebook, application/vnd.amazon.ebook	Kindle, Calibre	Amazon Kindle formats; MOBI is deprecated in favour of AZW3 and KFX.
.pages / .numbers / .key	Document	application/vnd.apple.pages (numbers, keynote)	Apple Pages, Numbers, Keynote	Apple iWork packages; export to PDF or Office formats for Windows users.
.tex	Text (typesetting)	application/x-tex	LaTeX editors	LaTeX source for scientific documents.
.csv	Data	text/csv	Excel, Sheets, any text editor	Comma-separated values; one table, no formatting or types.	JSON to CSV
.tsv	Data	text/tab-separated-values	Excel, Sheets, text editors	Tab-separated values; safer than CSV when fields contain commas.
.json	Data	application/json	Text editors, browsers	JavaScript Object Notation; the standard API data format.	Format JSON
.xml	Data	application/xml, text/xml	Text editors, browsers	Extensible Markup Language; verbose but supports schemas and namespaces.
.yaml / .yml	Data	application/yaml	Text editors	Human-readable configuration format (Docker Compose, GitHub Actions, Kubernetes).
.toml	Data	application/toml	Text editors	Configuration format used by Rust (Cargo) and Python (pyproject).
.ini / .cfg	Data	text/plain	Text editors	Simple key=value configuration files with [sections].
.sql	Data	application/sql	Database tools, text editors	SQL statements or a database dump.
.db / .sqlite	Database	application/vnd.sqlite3	SQLite tools, DB Browser	SQLite database file used by apps and phones.
.parquet	Data	application/vnd.apache.parquet	pandas, Spark, DuckDB	Columnar analytics format; not human-readable.
.ics	Data (calendar)	text/calendar	Calendar apps	iCalendar event or calendar export.
.vcf	Data (contacts)	text/vcard	Contacts apps	vCard contact export.
.gpx / .kml	Data (geo)	application/gpx+xml, application/vnd.google-earth.kml+xml	Maps, Garmin, Google Earth	GPS tracks and map overlays (both XML).
.zip	Archive	application/zip	Windows, macOS, every OS	Universal archive; many portals reject compressed uploads, so extract first.
.rar	Archive	application/vnd.rar	WinRAR, 7-Zip, The Unarchiver	Proprietary archive; needs a third-party extractor on most systems.
.7z	Archive	application/x-7z-compressed	7-Zip, Keka	High-compression open archive format.
.tar	Archive	application/x-tar	Linux, macOS, 7-Zip	Bundles files without compression; usually paired with gzip.
.gz / .tgz / .tar.gz	Archive	application/gzip	Linux, macOS, 7-Zip	Gzip-compressed file or tarball; standard on Unix.
.bz2 / .xz	Archive	application/x-bzip2, application/x-xz	Linux, macOS, 7-Zip	Higher-ratio compressors used for source distributions.
.iso	Disk image	application/x-iso9660-image	Mounts in Windows and macOS	Optical disc image; used for OS installers.
.dmg	Disk image	application/x-apple-diskimage	macOS	macOS installer disk image.
.exe	Executable	application/vnd.microsoft.portable-executable	Windows	Windows program; blocked by most email systems.
.msi	Installer	application/x-msi	Windows Installer	Windows installer package.
.apk	App package	application/vnd.android.package-archive	Android	Android app package (a ZIP).
.ipa	App package	application/octet-stream	iOS (via App Store / TestFlight)	iOS app archive; cannot be sideloaded without signing.
.app	Application	application/octet-stream	macOS	macOS application bundle (a folder).
.deb / .rpm	Package	application/vnd.debian.binary-package, application/x-rpm	Debian/Ubuntu, Fedora/RHEL	Linux software packages.
.jar	Java archive	application/java-archive	Java runtime	Java application or library (a ZIP).
.dll / .so / .dylib	Library	application/octet-stream	Operating system	Shared libraries for Windows, Linux and macOS.
.bat / .cmd / .sh	Script	text/plain, application/x-sh	Command prompt, shell	Windows batch and Unix shell scripts.
.ps1	Script	text/plain	PowerShell	PowerShell script.
.py	Source code	text/x-python	Python, any editor	Python source.
.js / .mjs	Source code	text/javascript	Browsers, Node.js, any editor	JavaScript source (IANA recommends text/javascript).
.jsx / .tsx	Source code	text/jsx, text/tsx (de facto)	Code editors, bundlers	React components in JavaScript or TypeScript.
.html / .htm	Web page	text/html	Any browser	Web page markup.
.css	Stylesheet	text/css	Browsers, editors	Cascading style sheets.
.java / .kt	Source code	text/x-java-source, text/x-kotlin	IDEs	Java and Kotlin source.
.c / .cpp / .h	Source code	text/x-c	IDEs, compilers	C and C++ source and headers.
.cs	Source code	text/plain	Visual Studio, Rider	C# source.
.go / .rs / .rb / .php / .swift	Source code	text/plain (language-specific de facto types)	IDEs, compilers	Go, Rust, Ruby, PHP and Swift source files.
.wasm	Binary	application/wasm	Browsers, runtimes	WebAssembly module; must be served with this MIME type for streaming compilation.
.ttf	Font	font/ttf	Every OS	TrueType font.
.otf	Font	font/otf	Every OS	OpenType font (TrueType or CFF outlines).
.woff / .woff2	Font	font/woff, font/woff2	Browsers	Compressed web fonts; WOFF2 is about 30% smaller.
.ai	Design (vector)	application/postscript	Adobe Illustrator	Illustrator file; export SVG or PDF for others.
.eps	Design (vector)	application/postscript	Illustrator, Inkscape, printers	Encapsulated PostScript, common in print workflows.
.indd	Design (layout)	application/x-indesign	Adobe InDesign	InDesign layout file.
.fig	Design	application/octet-stream	Figma	Figma design export.
.sketch	Design	application/octet-stream	Sketch (macOS)	Sketch document (a ZIP of JSON).
.xd	Design	application/vnd.adobe.xd	Adobe XD	Adobe XD prototype file.
.dwg / .dxf	CAD	image/vnd.dwg, image/vnd.dxf	AutoCAD, FreeCAD	AutoCAD native drawing and its exchange format.
.stl / .obj	3D model	model/stl, model/obj	Slicers, Blender	3D printing meshes and general 3D geometry.
.glb / .gltf	3D model	model/gltf-binary, model/gltf+json	Browsers (three.js), Blender	Web-friendly 3D scene format.
.blend	3D scene	application/x-blender	Blender	Blender project file.
.srt	Subtitles	application/x-subrip	VLC, video editors, YouTube	SubRip plain-text subtitles with timestamps.
.vtt	Subtitles	text/vtt	Browsers (HTML5 video)	WebVTT subtitles for web video.
.ass / .ssa	Subtitles	text/x-ssa	VLC, Aegisub	Styled subtitles (Advanced SubStation Alpha).
.torrent	Metadata	application/x-bittorrent	BitTorrent clients	Describes files to download over BitTorrent.
.log	Text	text/plain	Any text editor	Application or server log.
.eml / .msg	Email	message/rfc822, application/vnd.ms-outlook	Mail clients, Outlook	Saved email messages.
.pst / .ost	Email store	application/vnd.ms-outlook	Microsoft Outlook	Outlook mailbox files.
.bak	Backup	application/octet-stream	Depends on the original program	Generic backup copy; rename to the original extension to open.
.tmp	Temporary	application/octet-stream	Usually nothing	Temporary file left by a program; safe to delete when the program is closed.
.crdownload / .part	Partial download	application/octet-stream	Nothing until complete	Incomplete browser download (Chrome, Firefox).
.lnk	Shortcut	application/x-ms-shortcut	Windows	Windows shortcut, not the file itself.
.url / .webloc	Shortcut	text/uri-list	Windows, macOS	Saved web link.
.p12 / .pfx	Certificate	application/x-pkcs12	OS keychain, browsers	Certificate plus private key bundle, password protected.
.pem / .crt / .cer	Certificate	application/x-pem-file, application/x-x509-ca-cert	OS keychain, OpenSSL	X.509 certificates and keys in text (PEM) or binary (DER) form.
.ovpn	Config	application/x-openvpn-profile	OpenVPN clients	OpenVPN connection profile.
.qif / .ofx	Data (finance)	application/x-ofx	Accounting software	Bank statement exports.
.dat	Generic data	application/octet-stream	Depends on the program	Catch-all extension; the content decides what opens it.

Sources

Frequently asked questions

Can I change a file's format by renaming the extension?

No. Renaming photo.heic to photo.jpg does not change the bytes inside; the file is still HEIC and a strict upload form will reject it (GivenTool reports "contents do not match extension"). Use a converter that re-encodes the data.

Why does the portal say "unsupported media type" for my photo?

The server checks the Content-Type or the file signature and only accepts certain formats, usually JPEG and PNG. iPhone HEIC and WebP downloads are the usual culprits; convert them to JPG first.

What is the difference between .jpg and .jpeg?

Nothing. Both are JPEG images; .jpg dates from Windows systems that allowed only three-letter extensions. Every program accepts both.

Which extensions are dangerous to open from email?

Executables and scripts: .exe, .msi, .bat, .cmd, .ps1, .js, .jar, .scr and .vbs, plus Office files with macros (.docm, .xlsm). Most mail providers block the first group outright.

Why do some files show no extension?

Windows hides known extensions by default (File Explorer, View, File name extensions), and macOS hides them per file. The extension is still there; the OS just does not display it.

File extensions and MIME types

Extensions, types and MIME types

Sources

Frequently asked questions

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