What is Content Type?

Content Type: types and how it is processed by the browser.

Content Type

Content Type (MIME-Type) is a field in the web server’s Response Header that identifies to the browser the type of resource being sent to it.

The MIME type always consists of two pieces of information: the Media type and the Media subtype.

EXAMPLE: type/subtype

If this field is present, the work of the browser will be greatly reduced, and although it plays an important role from the point of view of efficiency, “Content Type” is not mandatory but only recommended.

The presence of the Content Type will prevent the browser from having to autonomously identify the type of the submitted file but it may happen that, despite the presence of the string, it tries to interpret it autonomously giving rise to the so-called “MIME_Sniffing” .

This browser self-management scenario can be limited by using a“nosniff” directive that will allow you to have complete control over the situation.

How many content types exist?

There are numerous types of Content Type introduced on the Web for resource recognition.

The following are the main applications:


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In addition to this Content Type indication just given there are for example:“text/css” | “text/xml” |“text/javascript


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If the image is “png”“image/png” will be used, for “SVG”“image/svg+xml” or more recently introduced“image/webp.


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For “AVI” videos,“video/avi” will be used.


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Bad Content

With Screaming Frog it will be very easy to monitor this element. By navigating to the“Security” tab, it will be possible to analyze it under“Bad Content.”

In this tab, using the relevant filters you will be able to extensively evaluate any URL where the actual content type does not match the content type set in the header. The Seo Spider will also tell you if any invalid MIME types were used. You can export all the data in detail simply with the “Export” button on the top window of Seo Spider.

This analysis with the tool is especially important when an X_Content-Type-Options: nosniff response header is set and the browser relies completely on the “Content Type” declaration.

Related Tab: Response Code | Sidebar | Report

Seo Spider Tab