Overview

Internet media types (aka MIME types) are small strings that describe the type of some digital content. Some example media types are:

  • text/html
  • image/jpeg
  • video/mp4

As you can see, the general format is: <major_type>/<minor_type>

There are hundreds of media types.

Allowing / blocking

Media types can be specified in Pluckeye rules to allow or block certain types of content. Here are some examples of commands you could use to add such rules:

To allow all images on Facebook:

pluck + allow facebook.com image/

To allow SVG images everywhere:

pluck + allow image/svg

To block Adobe Flash on a particular page:

pluck + block https://example.com/foo.html application/x-shockwave-flash

The general format of these commands is:

pluck <+ / -> <rule type> [host / url / ip address / port] <media type>

(See rules to understand what the terms in the general form mean.)

Major types

There are only a handful of useful major media types:

application
the largest major media type, having hundreds of sub-types
audio
audio content
font
a relatively young type used for new fonts
image
image content
text
words (text/css, text/html, and text/plain are the most important)
video
video content

Noteworthy types

application

application/javascript
The most common label for JavaScript.
application/msword
Old Microsoft Word documents (.doc).
application/octet-stream
A catch-all for binary content.
application/pdf
Most PDF files.
application/vnd.ms-powerpoint
Old Microsoft PowerPoint presentations (.ppt).
application/vnd.openxmlformats-officedocument.presentationml.presentation
Microsoft PowerPoint presentations (.pptx).
application/vnd.openxmlformats-officedocument.wordprocessingml.document
Microsoft Word documents (.docx)
application/x-shockwave-flash
Adobe Flash.
application/x-silverlight
Microsoft Silverlight.
application/zip
ZIP files.

image

image/png
The most common type of image.
image/svg
SVG images, which are not taken by cameras, but are created using gemoetric shapes. As such, they are not a concern for most who wish to avoid problematic images online.
image/vnd.microsoft.icon
The type for the little images that appear in browser tabs and bookmarks.

text

text/css
Stylesheets on web pages.
text/html
Normal web pages.
text/plain
Plain text (not too common on the web).

audio / video

audio/mpeg
MP3 files.
video/mp4
MP4 video files.

Finding a media type

You can determine the media type of a particular file using the mety command:

pluck mety foo.txt         # prints foo.txt -> text/plain

More media types