File Extensions Reference

A reference of common file extensions and the formats they represent, documents, images, audio and video, archives, and code and data files.

A file extension is the part of a filename after the last dot. It hints at the file's format and tells your operating system which app to open it with. The extension does not change the actual contents, renaming a .png to .jpg does not convert it.

Documents & text

ExtensionFormat
.txtPlain text
.pdfPortable Document Format
.doc / .docxMicrosoft Word
.xls / .xlsxMicrosoft Excel spreadsheet
.ppt / .pptxMicrosoft PowerPoint
.odtOpenDocument text
.rtfRich Text Format
.mdMarkdown
.csvComma-separated values
.epubE-book format

Images

ExtensionFormat
.jpg / .jpegCompressed photo (lossy)
.pngLossless image with transparency
.gifAnimated / simple images
.webpModern web image format
.svgScalable vector graphic (XML)
.heicHigh-efficiency image (HEIF/HEVC)
.tiffHigh-quality print image
.bmpBitmap image (usually uncompressed)
.icoIcon (favicons)

Audio & video

ExtensionFormat
.mp3Compressed audio
.wavWaveform audio (usually uncompressed PCM)
.flacLossless audio
.aac / .m4aAAC audio (.m4a is MP4 audio)
.mp4MPEG-4 video container
.movApple QuickTime video
.mkvMatroska video container
.webmOpen web video
.aviLegacy video container

Archives & disk

ExtensionFormat
.zipCompressed archive
.tarUncompressed Unix archive
.gzGzip-compressed file
.tar.gz / .tgzGzipped tarball
.7z7-Zip archive (high ratio)
.rarRAR archive
.isoDisc image
.dmgApple disk image

Code & data

ExtensionFormat
.htmlWeb page markup
.cssStylesheet
.js / .tsJavaScript / TypeScript
.pyPython script
.jsonJavaScript Object Notation
.xmlExtensible Markup Language
.yaml / .ymlYAML config
.sqlSQL script
.shShell script
.exeWindows executable

To see file extensions, enable them in your file manager (Windows File Explorer and macOS Finder usually hide them). Be cautious with executables (.exe, .sh, .bat) from untrusted sources.

What this does

A file extensions reference maps common extensions to the formats they represent — documents, images, audio and video, archives, and code and data files.

How to use it

  1. Find an extension.
  2. Read the format it represents.
  3. Note the category.
  4. Copy the extension with one tap.

Example

.csv is a plain-text spreadsheet of comma-separated values.

Last updated .

Frequently asked questions

Does changing a file extension convert the file?

No. The extension only labels the format; renaming a .png to .jpg does not convert the contents. Use a real converter to change a file’s format.

Why can’t I see file extensions?

Windows File Explorer and macOS Finder usually hide them. In File Explorer choose View > Show > File name extensions; on a Mac choose Finder > Settings > Advanced and select "Show all filename extensions".

Which extensions should I be cautious with?

Executable types such as .exe, .bat, and .sh can run code. Only open them from sources you trust.