MIME Types in IIS

John Meade, Web Technology Writer
Internet Information Services Documentation Team
Microsoft Corporation
July 19, 1999

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Multipurpose Internet Mail Extensions (MIME) is a specification for creating file formats to be used in the exchange of e-mail, in Web documents, and in other applications on intranets and on the Internet. Each MIME format includes a MIME content type ("MIME type") and subtype which denote the kind of data stored in the file. MIME types and subtypes are typically listed as type/subtype. For example, an MPEG video file would be listed as "video/mpeg." MIME type/subtype listings include acceptable file name extensions. For example, a table listing MIME information for an MPEG file might have an MPEG entry that appears as follows:

Type/Subtype Extensions
video/mpeg .mpe, .mpeg, .mpg

MIME-formatted content is widely used in Web documents. For example, you could link an MPEG file to a Web page. When a user viewing the page clicks on the MPEG-file link, Internet Information Services (IIS) and the Microsoft® Internet Explorer browser perform the following sequence of events when downloading the MPEG file to the browser for display:

  1. Along with the file, IIS sends the MIME type and subtype (video/mpeg, video/mpe, or video/mpg) to the browser.
  2. If support for the MPEG MIME format is built-in, the browser displays the file.
  3. If the browser does not contain built-in support for the MIME format, the browser looks up the file name extension in its table of helper applications. Then it either selects the appropriate helper application to display the file or returns an error message.

IIS includes a table of the most common Web-related mime types/subtypes and associated file name extensions. If IIS does not have MIME information for a MIME-formatted file that you download, then IIS will attach a default MIME identity to that file. As a result, the client receiving the file may misinterpret its contents. You can manually add MIME types, subtypes, and file name extensions to IIS for files whose MIME identity is not in the table. See the section on adding MIME types which applies to your version of IIS.

Note that when planning to use a MIME format, you must configure the browser for a helper application to process any MIME type not supported directly by the browser.

Using the MIME Tables

This reference contains two versions of the same MIME table:

If you have a MIME extension and want to find the MIME type/subtype used by IIS 4.0 or IIS 5.0, look it up in the first table, "MIME Formats in IIS, in Extension Order."

If you have a MIME type/subtype, and want to find out if it's registered in IIS 4.0 or IIS 5.0, look in the second table, "MIME Formats in IIS, in Type/Subtype Order." This table is also good for finding a file extension used for a given MIME type/subtype.

Adding MIME Types to IIS 4.0

MIME types can be registered in IIS 4.0 using the Internet Service Manager console.

For example, to add the XML MIME type using Internet Service Manager:

  1. Select Default Web Site and bring up the Properties dialog box.
  2. Select the HTTP Headers tab.
  3. Under MIME Map, click the File Types tab and select New Type.
  4. Type .xml in the Extension field and text/xml in the Content Type field, and then click OK.

Any other extensions, such as .xsl (eXtensible Style Sheets), may be added using the same procedures.

Adding MIME Types to IIS 5.0

MIME types can be registered in IIS 5.0 using the IIS snap-in.

For example, to add the XML MIME type to the default Web site using the IIS snap-in:

  1. Select Default Web Site and bring up the Properties dialog box.
  2. Select the HTTP Headers tab.
  3. Under MIME Map, click the File Types tab and select New Type.
  4. Type .xml in the Extension field and text/xml in the Content Type field, and then click OK.

To add the XML MIME type to all sites running on a given machine:

  1. Select Internet Information Services and bring up the Properties dialog box.
  2. Under Computer MIME Map, click the Edit button and select New Type.
  3. Type .xml in the Extension field and text/xml in the Content Type field, and then click OK.

Any other extensions, such as .xsl (eXtensible Style Sheets), may be added using the same procedures.

Declaring a MIME Type in an ASP Page

When a Web server returns a file to a browser, it sends information identifying the type of content being returned. When an ASP application is generating content other than HTML, it must declare a MIME type/subtype using the ContentType property of the Response object.

For example, when generating XML dynamically using ASP, the XML MIME type/subtype must be declared in the ASP file itself. Using the ContentType property of the Response object, indicate that the output is XML, as follows: <% Response.ContentType = "text/xml" %>

MIME Formats in IIS, in Extension Order

The following table lists the MIME content-types, listed in order of file name extensions, registered in IIS 4.0 and IIS 5.0.

IIS 4.0
IIS 5.0
* application/octet-stream Yes Yes
323 text/h323 No Yes
acx application/internet-property-stream No Yes
ai application/postscript Yes Yes
aif audio/x-aiff Yes Yes
aifc audio/x-aiff Yes Yes
aiff audio/x-aiff Yes Yes
asf video/x-ms-asf No Yes
asr video/x-ms-asf No Yes
asx video/x-ms-asf No Yes
au audio/basic Yes Yes
avi video/x-msvideo Yes Yes
axs application/olescript No Yes
bas text/plain Yes Yes
bcpio application/x-bcpio Yes Yes
bin application/octet-stream Yes Yes
bmp image/bmp Yes Yes
c text/plain Yes Yes
cat application/vnd.ms-pkiseccat No Yes
cdf application/x-cdf No Yes
cer application/x-x509-ca-cert No Yes
class application/octet-stream Yes Yes
clp application/x-msclip Yes Yes
cmx image/x-cmx Yes Yes
cod image/cis-cod Yes Yes
cpio application/x-cpio Yes Yes
crd application/x-mscardfile Yes Yes
crl application/pkix-crl No Yes
crt application/x-x509-ca-cert No Yes
csh application/x-csh Yes Yes
css text/css No Yes
dcr application/x-director Yes Yes
der application/x-x509-ca-cert No Yes
dir application/x-director Yes Yes
dll application/x-msdownload No Yes
dms application/octet-stream Yes Yes
doc application/msword Yes Yes
dot application/msword Yes Yes
dvi application/x-dvi Yes Yes
dxr application/x-director Yes Yes
eps application/postscript Yes Yes
etx text/x-setext Yes Yes
evy application/envoy Yes Yes
exe application/octet-stream Yes Yes
fif application/fractals No Yes
flr x-world/x-vrml Yes Yes
gif image/gif Yes Yes
gtar application/x-gtar Yes Yes
gz application/x-gzip No Yes
h text/plain Yes Yes
hdf application/x-hdf Yes Yes
hlp application/winhlp Yes Yes
hqx application/mac-binhex40 Yes Yes
hta application/hta No Yes
htc text/x-component No Yes
htm text/html Yes Yes
html text/html Yes Yes
htt text/webviewhtml No Yes
ico image/x-icon No Yes
ief image/ief Yes Yes
iii application/x-iphone No Yes
ins application/x-internet-signup No Yes
isp application/x-internet-signup No Yes
jfif image/pipeg No Yes
jpe image/jpeg Yes Yes
jpeg image/jpeg Yes Yes
jpg image/jpeg Yes Yes
js application/x-javascript Yes Yes
latex application/x-latex Yes Yes
lha application/octet-stream Yes Yes
lsf video/x-la-asf No Yes
lsx video/x-la-asf No Yes
lzh application/octet-stream Yes Yes
m13 application/x-msmediaview Yes Yes
m14 application/x-msmediaview Yes Yes
m3u audio/x-mpegurl No Yes
man application/x-troff-man Yes Yes
mdb application/x-msaccess Yes Yes
me application/x-troff-me Yes Yes
mht message/rfc822 No Yes
mhtml message/rfc822 No Yes
mid audio/mid No Yes
mny application/x-msmoney Yes Yes
mov video/quicktime Yes Yes
movie video/x-sgi-movie Yes Yes
mp2 video/mpeg Yes Yes
mp3 audio/mpeg No Yes
mpa video/mpeg Yes Yes
mpe video/mpeg Yes Yes
mpeg video/mpeg Yes Yes
mpg video/mpeg Yes Yes
mpp application/vnd.ms-project Yes Yes
mpv2 video/mpeg Yes Yes
ms application/x-troff-ms Yes Yes
mvb application/x-msmediaview Yes Yes
nws message/rfc822 No Yes
oda application/oda Yes Yes
p10 application/pkcs10 No Yes
p12 application/x-pkcs12 No Yes
p7b application/x-pkcs7-certificates No Yes
p7c application/x-pkcs7-mime No Yes
p7m application/x-pkcs7-mime No Yes
p7r application/x-pkcs7-certreqresp No Yes
p7s application/x-pkcs7-signature No Yes
pbm image/x-portable-bitmap Yes Yes
pdf application/pdf Yes Yes
pfx application/x-pkcs12 No Yes
pgm image/x-portable-graymap Yes Yes
pko application/ynd.ms-pkipko No Yes
pma application/x-perfmon Yes Yes
pmc application/x-perfmon Yes Yes
pml application/x-perfmon Yes Yes
pmr application/x-perfmon Yes Yes
pmw application/x-perfmon Yes Yes
pnm image/x-portable-anymap Yes Yes
pot, application/vnd.ms-powerpoint Yes Yes
ppm image/x-portable-pixmap Yes Yes
pps application/vnd.ms-powerpoint Yes Yes
ppt application/vnd.ms-powerpoint Yes Yes
prf application/pics-rules No Yes
ps application/postscript Yes Yes
pub application/x-mspublisher Yes Yes
qt video/quicktime Yes Yes
ra audio/x-pn-realaudio Yes Yes
ram audio/x-pn-realaudio Yes Yes
ras image/x-cmu-raster Yes Yes
rgb image/x-rgb Yes Yes
rmi audio/mid No Yes
roff application/x-troff Yes Yes
rtf application/rtf Yes Yes
rtx text/richtext Yes Yes
scd application/x-msschedule Yes Yes
sct text/scriptlet No Yes
setpay application/set-payment-initiation No Yes
setreg application/set-registration-initiation No Yes
sh application/x-sh Yes Yes
shar application/x-shar Yes Yes
sit application/x-stuffit No Yes
snd audio/basic Yes Yes
spc application/x-pkcs7-certificates No Yes
spl application/futuresplash No Yes
src application/x-wais-source Yes Yes
sst application/vnd.ms-pkicertstore No Yes
stl application/vnd.ms-pkistl No Yes
stm text/html Yes Yes
sv4cpio application/x-sv4cpio Yes Yes
sv4crc application/x-sv4crc Yes Yes
t application/x-troff Yes Yes
tar application/x-tar Yes Yes
tcl application/x-tcl Yes Yes
tex application/x-tex Yes Yes
texi application/x-texinfo Yes Yes
texinfo application/x-texinfo Yes Yes
tgz application/x-compressed No Yes
tif image/tiff Yes Yes
tiff image/tiff Yes Yes
tr application/x-troff Yes Yes
trm application/x-msterminal Yes Yes
tsv text/tab-separated-values Yes Yes
txt text/plain Yes Yes
uls text/iuls No Yes
ustar application/x-ustar Yes Yes
vcf text/x-vcard No Yes
vrml x-world/x-vrml Yes Yes
wav audio/x-wav Yes Yes
wcm application/vnd.ms-works Yes Yes
wdb application/vnd.ms-works Yes Yes
wks application/vnd.ms-works Yes Yes
wmf application/x-msmetafile Yes Yes
wps application/vnd.ms-works Yes Yes
wri application/x-mswrite Yes Yes
wrl x-world/x-vrml Yes Yes
wrz x-world/x-vrml Yes Yes
xaf x-world/x-vrml Yes Yes
xbm image/x-xbitmap Yes Yes
xla application/vnd.ms-excel Yes Yes
xlc application/vnd.ms-excel Yes Yes
xlm application/vnd.ms-excel Yes Yes
xls application/vnd.ms-excel Yes Yes
xlt application/vnd.ms-excel Yes Yes
xlw application/vnd.ms-excel Yes Yes
xof x-world/x-vrml Yes Yes
xpm image/x-xpixmap Yes Yes
xwd image/x-xwindowdump Yes Yes
z application/x-compress No Yes
zip application/zip Yes Yes

MIME Formats in IIS, in Type/Subtype Order

The following table lists the MIME content-types, listed in order of MIME content type/subtype, registered in IIS 4.0 and IIS 5.0.

Type/sub-type Extension IIS 4.0 IIS 5.0
application/envoy evy Yes Yes
application/fractals fif No Yes
application/futuresplash spl No Yes
application/hta hta No Yes
application/internet-property-stream acx No Yes
application/mac-binhex40 hqx Yes Yes
application/msword doc Yes Yes
application/msword dot Yes Yes
application/octet-stream * Yes Yes
application/octet-stream bin Yes Yes
application/octet-stream class Yes Yes
application/octet-stream dms Yes Yes
application/octet-stream exe Yes Yes
application/octet-stream lha Yes Yes
application/octet-stream lzh Yes Yes
application/oda oda Yes Yes
application/olescript axs No Yes
application/pdf pdf Yes Yes
application/pics-rules prf No Yes
application/pkcs10 p10 No Yes
application/pkix-crl crl No Yes
application/postscript ai Yes Yes
application/postscript eps Yes Yes
application/postscript ps Yes Yes
application/rtf rtf Yes Yes
application/set-payment-initiation setpay No Yes
application/set-registration-initiation setreg No Yes
application/vnd.ms-excel xla Yes Yes
application/vnd.ms-excel xlc Yes Yes
application/vnd.ms-excel xlm Yes Yes
application/vnd.ms-excel xls Yes Yes
application/vnd.ms-excel xlt Yes Yes
application/vnd.ms-excel xlw Yes Yes
application/vnd.ms-pkicertstore sst No Yes
application/vnd.ms-pkiseccat cat No Yes
application/vnd.ms-pkistl stl No Yes
application/vnd.ms-powerpoint pot, Yes Yes
application/vnd.ms-powerpoint pps Yes Yes
application/vnd.ms-powerpoint ppt Yes Yes
application/vnd.ms-project mpp Yes Yes
application/vnd.ms-works wcm Yes Yes
application/vnd.ms-works wdb Yes Yes
application/vnd.ms-works wks Yes Yes
application/vnd.ms-works wps Yes Yes
application/winhlp hlp Yes Yes
application/x-bcpio bcpio Yes Yes
application/x-cdf cdf No Yes
application/x-compress z No Yes
application/x-compressed tgz No Yes
application/x-cpio cpio Yes Yes
application/x-csh csh Yes Yes
application/x-director dcr Yes Yes
application/x-director dir Yes Yes
application/x-director dxr Yes Yes
application/x-dvi dvi Yes Yes
application/x-gtar gtar Yes Yes
application/x-gzip gz No Yes
application/x-hdf hdf Yes Yes
application/x-internet-signup ins No Yes
application/x-internet-signup isp No Yes
application/x-iphone iii No Yes
application/x-javascript js Yes Yes
application/x-latex latex Yes Yes
application/x-msaccess mdb Yes Yes
application/x-mscardfile crd Yes Yes
application/x-msclip clp Yes Yes
application/x-msdownload dll No Yes
application/x-msmediaview m13 Yes Yes
application/x-msmediaview m14 Yes Yes
application/x-msmediaview mvb Yes Yes
application/x-msmetafile wmf Yes Yes
application/x-msmoney mny Yes Yes
application/x-mspublisher pub Yes Yes
application/x-msschedule scd Yes Yes
application/x-msterminal trm Yes Yes
application/x-mswrite wri Yes Yes
application/x-netcdf cdf Yes Yes
application/x-netcdf nc Yes Yes
application/x-perfmon pma Yes Yes
application/x-perfmon pmc Yes Yes
application/x-perfmon pml Yes Yes
application/x-perfmon pmr Yes Yes
application/x-perfmon pmw Yes Yes
application/x-pkcs12 p12 No Yes
application/x-pkcs12 pfx No Yes
application/x-pkcs7-certificates p7b No Yes
application/x-pkcs7-certificates spc No Yes
application/x-pkcs7-certreqresp p7r No Yes
application/x-pkcs7-mime p7c No Yes
application/x-pkcs7-mime p7m No Yes
application/x-pkcs7-signature p7s No Yes
application/x-sh sh Yes Yes
application/x-shar shar Yes Yes
application/x-stuffit sit No Yes
application/x-sv4cpio sv4cpio Yes Yes
application/x-sv4crc sv4crc Yes Yes
application/x-tar tar Yes Yes
application/x-tcl tcl Yes Yes
application/x-tex tex Yes Yes
application/x-texinfo texi Yes Yes
application/x-texinfo texinfo Yes Yes
application/x-troff roff Yes Yes
application/x-troff t Yes Yes
application/x-troff tr Yes Yes
application/x-troff-man man Yes Yes
application/x-troff-me me Yes Yes
application/x-troff-ms ms Yes Yes
application/x-ustar ustar Yes Yes
application/x-wais-source src Yes Yes
application/x-x509-ca-cert cer No Yes
application/x-x509-ca-cert crt No Yes
application/x-x509-ca-cert der No Yes
application/ynd.ms-pkipko pko No Yes
application/zip zip Yes Yes
audio/basic au Yes Yes
audio/basic snd Yes Yes
audio/mid mid No Yes
audio/mid rmi No Yes
audio/mpeg mp3 No Yes
audio/x-aiff aif Yes Yes
audio/x-aiff aifc Yes Yes
audio/x-aiff aiff Yes Yes
audio/x-mpegurl m3u No Yes
audio/x-pn-realaudio ra Yes Yes
audio/x-pn-realaudio ram Yes Yes
audio/x-wav wav Yes Yes
image/bmp bmp Yes Yes
image/cis-cod cod Yes Yes
image/gif gif Yes Yes
image/ief ief Yes Yes
image/jpeg jpe Yes Yes
image/jpeg jpeg Yes Yes
image/jpeg jpg Yes Yes
image/pipeg jfif No Yes
image/tiff tif Yes Yes
image/tiff tiff Yes Yes
image/x-cmu-raster ras Yes Yes
image/x-cmx cmx Yes Yes
image/x-icon ico No Yes
image/x-portable-anymap pnm Yes Yes
image/x-portable-bitmap pbm Yes Yes
image/x-portable-graymap pgm Yes Yes
image/x-portable-pixmap ppm Yes Yes
image/x-rgb rgb Yes Yes
image/x-xbitmap xbm Yes Yes
image/x-xpixmap xpm Yes Yes
image/x-xwindowdump xwd Yes Yes
message/rfc822 mht No Yes
message/rfc822 mhtml No Yes
message/rfc822 nws No Yes
text/css css No Yes
text/h323 323 No Yes
text/html htm Yes Yes
text/html html Yes Yes
text/html stm Yes Yes
text/iuls uls No Yes
text/plain bas Yes Yes
text/plain c Yes Yes
text/plain h Yes Yes
text/plain txt Yes Yes
text/richtext rtx Yes Yes
text/scriptlet sct No Yes
text/tab-separated-values tsv Yes Yes
text/webviewhtml htt No Yes
text/x-component htc No Yes
text/x-setext etx Yes Yes
text/x-vcard vcf No Yes
video/mpeg mp2 Yes Yes
video/mpeg mpa Yes Yes
video/mpeg mpe Yes Yes
video/mpeg mpeg Yes Yes
video/mpeg mpg Yes Yes
video/mpeg mpv2 Yes Yes
video/quicktime mov Yes Yes
video/quicktime qt Yes Yes
video/x-la-asf lsf No Yes
video/x-la-asf lsx No Yes
video/x-ms-asf asf No Yes
video/x-ms-asf asr No Yes
video/x-ms-asf asx No Yes
video/x-msvideo avi Yes Yes
video/x-sgi-movie movie Yes Yes
x-world/x-vrml flr Yes Yes
x-world/x-vrml vrml Yes Yes
x-world/x-vrml wrl Yes Yes
x-world/x-vrml wrz Yes Yes
x-world/x-vrml xaf Yes Yes
x-world/x-vrml xof Yes Yes



comp.mail.mime FAQ
This extensive FAQ on MIME is posted approximately monthly to the newsgroup comp.mail.mime. An automatically generated HTML version of the MIME FAQ is available at this URL: http://www.cis.ohio-state.edu/text/faq/usenet/mail/mime-faq/top.html

Last updated November 13, 2000

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