It takes your upload and stores a temporary file, which is then inspected to see what the MIME type is. It does not rely on the file extension to complete the task. All files uploaded via the https protocol and are immediately deleted after inspection. Max file upload size: 50MB (this can be raised).
Well, at least the ones you are most commonly going to encounter. There is an untold number of more exotic MIME's such as application/x-bittorrent and application/x-iso9660-image etc.
Suffixes applicable
Media type and subtype(s)
.a
application/octet-stream
.aab
application/x-authorware-bin
.aam
application/x-authorware-map
.aas
application/x-authorware-seg
.ai
application/postscript
.aip
text/x-audiosoft-intra
.ani
application/x-navi-animation
.aos
application/x-nokia-9000-communicator-add-on-software
.arc
application/octet-stream
.arj
application/octet-stream
.asx
application/x-mplayer2
.asx
video/x-ms-asf-plugin
.avi
application/x-troff-msvideo
.bcpio
application/x-bcpio
.bin
application/mac-binary
.bin
application/macbinary
.bin
application/octet-stream
.bin
application/x-binary
.bin
application/x-macbinary
.cat
application/vnd.ms-pki.seccat
.ccad
application/clariscad
.cdf
application/x-netcdf
.cer
application/pkix-cert
.cer
application/x-x509-ca-cert
.class
application/java-byte-code
.class
application/x-java-class
.com
application/octet-stream
.cpt
application/mac-compactpro
.cpt
application/x-compactpro
.crl
application/pkcs-crl
.crl
application/pkix-crl
.crt
application/pkix-cert
.crt
application/x-x509-ca-cert
.crt
application/x-x509-user-cert
.css
application/x-pointplus
.dcr
application/x-director
.deepv
application/x-deepv
.der
application/x-x509-ca-cert
.dir
application/x-director
.dp
application/commonground
.drw
application/drafting
.dump
application/octet-stream
.dxr
application/x-director
.elc
application/x-bytecode.elisp (compiled elisp)
.eps
application/postscript
.es
application/x-esrehber
.exe
application/octet-stream
.fif
application/fractals
.flx
text/vnd.fmi.flexstor
.fmf
video/x-atomic3d-feature
.frl
application/freeloader
.gz
application/x-compressed
.help
application/x-helpfile
.hgl
application/vnd.hp-hpgl
.hlp
application/x-helpfile
.hlp
application/x-winhelp
.hpg
application/vnd.hp-hpgl
.hpgl
application/vnd.hp-hpgl
.hqx
application/mac-binhex
.hqx
application/mac-binhex40
.hqx
application/x-binhex40
.hqx
application/x-mac-binhex40
.ice
x-conference/x-cooltalk
.imap
application/x-httpd-imap
.ins
application/x-internett-signup
.iv
application/x-inventor
.ivy
application/x-livescreen
.jcm
application/x-java-commerce
.js
application/x-javascript
.js
application/javascript
.js
application/ecmascript
.latex
application/x-latex
.lha
application/octet-stream
.lhx
application/octet-stream
.lzh
application/octet-stream
.lzx
application/octet-stream
.man
application/x-troff-man
.map
application/x-navimap
.mc$
application/x-magic-cap-package-1.0
.mcd
application/x-mathcad
.me
application/x-troff-me
.mjf
audio/x-vnd.audioexplosion.mjuicemediafile
.mjpg
video/x-motion-jpeg
.mpc
application/x-project
.mpp
application/vnd.ms-project
.mpt
application/x-project
.mpv
application/x-project
.mpx
application/x-project
.ms
application/x-troff-ms
.mzz
application/x-vnd.audioexplosion.mzz
.ncm
application/vnd.nokia.configuration-message
.nix
application/x-mix-transfer
.nsc
application/x-conference
.nvd
application/x-navidoc
.o
application/octet-stream
.omcd
application/x-omcdatamaker
.omcr
application/x-omcregerator
.p10
application/x-pkcs10
.p12
application/x-pkcs12
.p7a
application/x-pkcs7-signature
.p7c
application/pkcs7-mime
.p7c
application/x-pkcs7-mime
.p7m
application/pkcs7-mime
.p7m
application/x-pkcs7-mime
.p7r
application/x-pkcs7-certreqresp
.p7s
application/pkcs7-signature
.part
application/pro_eng
.pbm
image/x-pordiv-bitmap
.pcl
application/vnd.hp-pcl
.pfunk
audio/make.my.funk
.pgm
image/x-pordiv-graymap
.pgm
image/x-pordiv-greymap
.pkg
application/x-newton-compatible-pkg
.pko
application/vnd.ms-pki.pko
.plx
application/x-pixclscript
.pm
text/x-script.perl-module
.pm4
application/x-pagemaker
.pm5
application/x-pagemaker
.pnm
application/x-pordiv-anymap
.pnm
image/x-pordiv-anymap
.pot
application/mspowerpoint
.pot
application/vnd.ms-powerpoint
.ppa
application/vnd.ms-powerpoint
.ppm
image/x-pordiv-pixmap
.pps
application/mspowerpoint
.pps
application/vnd.ms-powerpoint
.ppt
application/mspowerpoint
.ppt
application/powerpoint
.ppt
application/vnd.ms-powerpoint
.ppt
application/x-mspowerpoint
.ppz
application/mspowerpoint
.pre
application/x-freelance
.ps
application/postscript
.psd
application/octet-stream
.pwz
application/vnd.ms-powerpoint
.pyc
application/x-bytecode.python
.ra
audio/x-pn-realaudio-plugin
.ram
audio/x-pn-realaudio
.ras
application/x-cmu-raster
.rf
image/vnd.rn-realflash
.rm
application/vnd.rn-realmedia
.rmm
audio/x-pn-realaudio
.rmp
audio/x-pn-realaudio
.rmp
audio/x-pn-realaudio-plugin
.rng
application/ringing-tones
.rng
application/vnd.nokia.ringing-tone
.rnx
application/vnd.rn-realplayer
.roff
application/x-troff
.rpm
audio/x-pn-realaudio-plugin
.rv
video/vnd.rn-realvideo
.saveme
application/octet-stream
.scm
application/x-lotusscreencam
.scm
text/x-script.scheme
.shtml
text/x-server-parsed-html
.sit
application/x-stuffit
.sl
application/x-seelogo
.spc
application/x-pkcs7-certificates
.spl
application/futuresplash
.spr
application/x-sprite
.sprite
application/x-sprite
.src
application/x-wais-source
.ssi
text/x-server-parsed-html
.ssm
application/streamingmedia
.sst
application/vnd.ms-pki.certstore
.stl
application/vnd.ms-pki.stl
.stl
application/x-navistyle
.sv4cpio
application/x-sv4cpio
.sv4crc
application/x-sv4crc
.swf
application/x-shockwave-flash
.tbk
application/toolbook
.texi
application/x-texinfo
.texinfo
application/x-texinfo
.tgz
application/x-compressed
.tsv
text/tab-separated-values
.ustar
application/x-ustar
.uu
application/octet-stream
.vcd
application/x-cdlink
.vew
application/groupwise
.vmd
application/vocaltec-media-desc
.vmf
application/vocaltec-media-file
.vqe
audio/x-twinvq-plugin
.vql
audio/x-twinvq-plugin
.w60
application/wordperfect6.0
.w61
application/wordperfect6.1
.web
application/vnd.xara
.wmlc
application/vnd.wap.wmlc
.wmls
text/vnd.wap.wmlscript
.wmlsc
application/vnd.wap.wmlscriptc
.wp
application/wordperfect
.wp5
application/wordperfect
.wp5
application/wordperfect6.0
.wp6
application/wordperfect
.wpd
application/wordperfect
.wsrc
application/x-wais-source
.wtk
application/x-wintalk
.xla
application/x-msexcel
.xlb
application/vnd.ms-excel
.xlc
application/vnd.ms-excel
.xll
application/vnd.ms-excel
.xlm
application/vnd.ms-excel
.xls
application/vnd.ms-excel
.xls
application/x-msexcel
.xlw
application/vnd.ms-excel
.xlw
application/x-msexcel
.xpix
application/x-vnd.ls-xpix
.z
application/x-compress
.z
application/x-compressed
.zip
application/x-compressed
.zip
application/x-zip-compressed
.zoo
application/octet-stream