Content Sniffing Data
Data as of September 26, 2008
Content-Types That Activated the Sniffer
Scale: out of 100%. Only responses with these Content-Types will activate the content sniffer. Not all mime types can be sniffed from all Content-Types. No data was recorded about what percent of requests activate the sniffer.
| Content-Type | Quantity |
|---|---|
| text/plain | 32.64% |
| text/xml | 30.38% |
| (No Content-Type) | 14.25% |
| application/octet-stream | 12.90% |
| application/xml | 9.71% |
| (Bogus, aka no "/") | 0.0833% |
| application/unknown | 0.0201% |
| unknown/unknown | 0.0144% |
| */* | 0.0057% |
Magic Numbers
Scale: out of 100%. The content sniffer looks for the magic number (expressed here in C notation) at the start of the HTTP response. The sniffer only examines HTTP responses with certain Content-Type headers (see below), so this data reflects only responses with those Content-Type headers.
| Magic Number | Sniffed Content Type | Quantity |
|---|---|---|
| \xFF\xD8\xFF | image/jpeg | 73.2369% |
| GIF89a | image/gif | 16.8166% |
| \x89PNG\x0D\x0A\x1A\x0A | image/png | 6.8840% |
| MZ | application/octet-stream | 0.9108% |
| Rar!\x1A\x07\x00 | application/x-rar-compressed | 0.6699% |
| BM | image/bmp | 0.3730% |
| GIF87a | image/gif | 0.3141% |
| "\x30\x26\xB2\x75\x8E\x66\xCF\x11" "\xA6\xD9\x00\xAA\x00\x62\xCE\x6C" | video/x-ms-asf | 0.2431% |
| PK\x03\x04 | application/zip | 0.2178% |
| ID3 | audio/mpeg | 0.1772% |
| %PDF- | application/pdf | 0.07913% |
| \x1F\x8B\x08 | application/x-gzip | 0.03149% |
| \x2E\x52\x4D\x46 | audio/x-pn-realaudio | 0.02904% |
| \xD7\xCD\xC6\x9A | application/x-msmetafile | 0.004032% |
| LN\x02\x00 | application/winhlp | 0.002070% |
| \xC5\xD0\xD3\xC6 | application/postscript | 0.001940% |
| {\\rtf1 | application/rtf | 0.001589% |
| \x4A\x47\x04\x0E\x00\x00\x00 | image/x-jg | 0.001193% |
| #! | text/plain | 0.001185% |
| II* | image/tiff | < 0.001% |
| "\x7F" "ELF" | application/octet-stream | < 0.001% |
| \xE9 | application/octet-stream | < 0.001% |
| \xE8 | application/octet-stream | < 0.001% |
| %!PS-Adobe- | application/postscript | < 0.001% |
| \xEB | application/octet-stream | < 0.001% |
| From | text/plain | < 0.001% |
| MM\x00* | image/tiff | < 0.001% |
| \x1F\x9D\x90 | application/x-compress | < 0.001% |
| ?_\x03 | application/winhlp | < 0.001% |
| \x00\x00\x20\x00 | image/x-icon | < 0.001% |
| \x4A\x47\x03\x0E\x00\x00\x00 | image/x-jg | < 0.001% |
| #define\x20 | image/x-xbitmap | < 0.001% |
| \x00\x00\x10\x00 | image/x-icon | < 0.001% |
| #% | text/plain | < 0.001% |
| P5\x0A | image/x-portable-graymap | < 0.001% |
| ">\x20" "From" | text/plain | none |
| \x01\xDA\x01\x01\x00\x03 | image/x-rgb | none |
| BZ | application/x-bzip2 | none |
| I\x20I | image/tiff | none |
| \x4A\x47\x04\x0E\x00\x00\x00 | image/x-jg | none |
| {\\rtf1 | application/rtf | none |
Byte Order Marks
Scale: out of 22.52%. The sniffer checks for a byte order mark at the beginning if certain HTTP responses.
| Mark | Charset | Quantity |
|---|---|---|
| \xEF\xBB\xBF | UTF-8 | 17.4296% |
| \xFF\xFE | UTF-16LE | 5.0548% |
| \xFE\xFF | UTF-16BE | 0.03246% |
| \x00\x00\xFE\xFF | UCS-4BE | < 0.0001% |
HTML Tags
Scale: out of 22.19%. When scanning for HTML tags, the sniffer first skips any leading white space and then looks for the tags below. The checks are case insensitive, except for "<?xml".
| Tag | Quantity |
|---|---|
| <script | 20.1647% |
| <html | 1.5660% |
| <?xml | 1.3761% |
| <!-- | 0.5394% |
| <head | 0.3771% |
| <!DOCTYPE html | 0.3299% |
| <iframe | 0.3210% |
| <h1 | 0.2700% |
| <div | 0.07008% |
| <font | 0.05681% |
| <table | 0.04286% |
| <a | 0.03166% |
| <style | 0.01501% |
| <title | 0.01174% |
| <b | 0.003531% |
| <body | 0.002923% |
| <br | 0.002834% |
| <p | 0.002581% |
| <meta | 0.001616% |
| <form | 0.001345% |
| <img | 0.001251% |
| <center | < 0.001% |
| <h3 | < 0.001% |
| <tr | < 0.001% |
| <link | < 0.001% |
| <h2 | < 0.001% |
| <frameset | < 0.001% |
| <h4 | < 0.001% |
| <base | < 0.001% |
| <td | < 0.001% |
| <pre | < 0.001% |
| <basefont | none |
| <applet | none |
| <isindex | none |
| <h5 | none |
| <h6 | none |