Proper MIME media type for PDF files

pdf http-headers content-type mime
friedo picture friedo · Nov 23, 2008 · Viewed 865.1k times · Source

When working with PDFs, I've run across the MIME types application/pdf and application/x-pdf among others.

Is there a difference between these two types, and if so what is it? Is one preferred over the other?

I'm working on a web app which must deliver huge amounts of PDFs and I want to do it the correct way, if there is one.

Answer

Chris Hanson picture Chris Hanson · Nov 23, 2008

The standard MIME type is application/pdf. The assignment is defined in RFC 3778, The application/pdf Media Type, referenced from the MIME Media Types registry.

MIME types are controlled by a standards body, The Internet Assigned Numbers Authority (IANA). This is the same organization that manages the root name servers and the IP address space.

The use of x-pdf predates the standardization of the MIME type for PDF. MIME types in the x- namespace are considered experimental, just as those in the vnd. namespace are considered vendor-specific. x-pdf might be used for compatibility with old software.

Related questions

How do I force files to open in the browser instead of downloading (PDF)?

Is there a way to force PDF files to open in the browser when the option "Display PDF in browser" is unchecked? I tried using the embed tag and an iframe, but it only works when that option is checked. …

Read More
Duplicate headers received from server

Duplicate headers received from server The response from the server contained duplicate headers. This problem is generally the result of a misconfigured website or proxy. Only the website or proxy administrator can fix this issue. Error 349 (net::ERR_RESPONSE_HEADERS_…

Read More
using header() to rewrite filename in URL for dynamic pdf

I have a php script that generates a pdf report. When we go to save the pdf document, the filename that Acrobat suggests is report_pdf, since the php script is named report_pdf.php. I would like to dynamically …

Read More