This script contains code which can determine the browser and platform on which it's running.
You simply include the following script block in any web page you create. Since it declares all sorts of variables, it should be outside any function block, so that all the symbols are available to any scripting in the HTML page.
// Ultimate client-side JavaScript client sniff. // (C) Netscape Communications 1999. Permission granted to reuse and distribute. // Revised 17 May 99 to add is_nav5up and is_ie5up (see below). // Everything you always wanted to know about your JavaScript client // but were afraid to ask. Creates "is_" variables indicating: // (1) browser vendor: // is_nav, is_ie, is_opera // (2) browser version number: // is_major (integer indicating major version number: 2, 3, 4 ...) // is_minor (float indicating full version number: 2.02, 3.01, 4.04 ...) // (3) browser vendor AND major version number // is_nav2, is_nav3, is_nav4, is_nav4up, is_nav5, is_nav5up, is_ie3, is_ie4, is_ie4up // (4) JavaScript version number: // is_js (float indicating full JavaScript version number: 1, 1.1, 1.2 ...) // (5) OS platform and version: // is_win, is_win16, is_win32, is_win31, is_win95, is_winnt, is_win98 // is_os2 // is_mac, is_mac68k, is_macppc // is_unix // is_sun, is_sun4, is_sun5, is_suni86 // is_irix, is_irix5, is_irix6 // is_hpux, is_hpux9, is_hpux10 // is_aix, is_aix1, is_aix2, is_aix3, is_aix4 // is_linux, is_sco, is_unixware, is_mpras, is_reliant // is_dec, is_sinix, is_freebsd, is_bsd // is_vms // // See http://www.it97.de/JavaScript/JS_tutorial/bstat/navobj.html and // http://www.it97.de/JavaScript/JS_tutorial/bstat/Browseraol.html // for detailed lists of userAgent strings. // // Note: you don't want your Nav4 or IE4 code to "turn off" or // stop working when Nav5 and IE5 (or later) are released, so // in conditional code forks, use is_nav4up ("Nav4 or greater") // and is_ie4up ("IE4 or greater") instead of is_nav4 or is_ie4 // to check version in code which you want to work on future // versions. // convert all characters to lowercase to simplify testing var agt=navigator.userAgent.toLowerCase(); // *** BROWSER VERSION *** // Note: On IE5, these return 4, so use is_ie5up to detect IE5. var is_major = parseInt(navigator.appVersion); var is_minor = parseFloat(navigator.appVersion); // Note: Opera and WebTV spoof Navigator. We do strict client detection. // If you want to allow spoofing, take out the tests for opera and webtv. var is_nav = ((agt.indexOf('mozilla')!=-1) && (agt.indexOf('spoofer')==-1) && (agt.indexOf('compatible') == -1) && (agt.indexOf('opera')==-1) && (agt.indexOf('webtv')==-1)); var is_nav2 = (is_nav && (is_major == 2)); var is_nav3 = (is_nav && (is_major == 3)); var is_nav4 = (is_nav && (is_major == 4)); var is_nav4up = (is_nav && (is_major >= 4)); var is_navonly = (is_nav && ((agt.indexOf(";nav") != -1) || (agt.indexOf("; nav") != -1)) ); var is_nav5 = (is_nav && (is_major == 5)); var is_nav5up = (is_nav && (is_major >= 5)); var is_ie = (agt.indexOf("msie") != -1); var is_ie3 = (is_ie && (is_major < 4)); var is_ie4 = (is_ie && (is_major == 4) && (agt.indexOf("msie 5.0")==-1) ); var is_ie4up = (is_ie && (is_major >= 4)); var is_ie5 = (is_ie && (is_major == 4) && (agt.indexOf("msie 5.0")!=-1) ); var is_ie5up = (is_ie && !is_ie3 && !is_ie4); // KNOWN BUG: On AOL4, returns false if IE3 is embedded browser // or if this is the first browser window opened. Thus the // variables is_aol, is_aol3, and is_aol4 aren't 100% reliable. var is_aol = (agt.indexOf("aol") != -1); var is_aol3 = (is_aol && is_ie3); var is_aol4 = (is_aol && is_ie4); var is_opera = (agt.indexOf("opera") != -1); var is_webtv = (agt.indexOf("webtv") != -1); // *** JAVASCRIPT VERSION CHECK *** var is_js; if (is_nav2 || is_ie3) is_js = 1.0 else if (is_nav3 || is_opera) is_js = 1.1 else if ((is_nav4 && (is_minor <= 4.05)) || is_ie4) is_js = 1.2 else if ((is_nav4 && (is_minor > 4.05)) || is_ie5) is_js = 1.3 else if (is_nav5) is_js = 1.4 // NOTE: In the future, update this code when newer versions of JS // are released. For now, we try to provide some upward compatibility // so that future versions of Nav and IE will show they are at // *least* JS 1.x capable. Always check for JS version compatibility // with > or >=. else if (is_nav && (is_major > 5)) is_js = 1.4 else if (is_ie && (is_major > 5)) is_js = 1.3 // HACK: no idea for other browsers; always check for JS version with > or >= else is_js = 0.0; // *** PLATFORM *** var is_win = ( (agt.indexOf("win")!=-1) || (agt.indexOf("16bit")!=-1) ); // NOTE: On Opera 3.0, the userAgent string includes "Windows 95/NT4" on all // Win32, so you can't distinguish between Win95 and WinNT. var is_win95 = ((agt.indexOf("win95")!=-1) || (agt.indexOf("windows 95")!=-1)); // is this a 16 bit compiled version? var is_win16 = ((agt.indexOf("win16")!=-1) || (agt.indexOf("16bit")!=-1) || (agt.indexOf("windows 3.1")!=-1) || (agt.indexOf("windows 16-bit")!=-1) ); var is_win31 = ((agt.indexOf("windows 3.1")!=-1) || (agt.indexOf("win16")!=-1) || (agt.indexOf("windows 16-bit")!=-1)); // NOTE: Reliable detection of Win98 may not be possible. It appears that: // - On Nav 4.x and before you'll get plain "Windows" in userAgent. // - On Mercury client, the 32-bit version will return "Win98", but // the 16-bit version running on Win98 will still return "Win95". var is_win98 = ((agt.indexOf("win98")!=-1) || (agt.indexOf("windows 98")!=-1)); var is_winnt = ((agt.indexOf("winnt")!=-1) || (agt.indexOf("windows nt")!=-1)); var is_win32 = (is_win95 || is_winnt || is_win98 || ((is_major >= 4) && (navigator.platform == "Win32")) || (agt.indexOf("win32")!=-1) || (agt.indexOf("32bit")!=-1)); var is_os2 = ((agt.indexOf("os/2")!=-1) || (navigator.appVersion.indexOf("OS/2")!=-1) || (agt.indexOf("ibm-webexplorer")!=-1)); var is_mac = (agt.indexOf("mac")!=-1); var is_mac68k = (is_mac && ((agt.indexOf("68k")!=-1) || (agt.indexOf("68000")!=-1))); var is_macppc = (is_mac && ((agt.indexOf("ppc")!=-1) || (agt.indexOf("powerpc")!=-1))); var is_sun = (agt.indexOf("sunos")!=-1); var is_sun4 = (agt.indexOf("sunos 4")!=-1); var is_sun5 = (agt.indexOf("sunos 5")!=-1); var is_suni86= (is_sun && (agt.indexOf("i86")!=-1)); var is_irix = (agt.indexOf("irix") !=-1); // SGI var is_irix5 = (agt.indexOf("irix 5") !=-1); var is_irix6 = ((agt.indexOf("irix 6") !=-1) || (agt.indexOf("irix6") !=-1)); var is_hpux = (agt.indexOf("hp-ux")!=-1); var is_hpux9 = (is_hpux && (agt.indexOf("09.")!=-1)); var is_hpux10= (is_hpux && (agt.indexOf("10.")!=-1)); var is_aix = (agt.indexOf("aix") !=-1); // IBM var is_aix1 = (agt.indexOf("aix 1") !=-1); var is_aix2 = (agt.indexOf("aix 2") !=-1); var is_aix3 = (agt.indexOf("aix 3") !=-1); var is_aix4 = (agt.indexOf("aix 4") !=-1); var is_linux = (agt.indexOf("inux")!=-1); var is_sco = (agt.indexOf("sco")!=-1) || (agt.indexOf("unix_sv")!=-1); var is_unixware = (agt.indexOf("unix_system_v")!=-1); var is_mpras = (agt.indexOf("ncr")!=-1); var is_reliant = (agt.indexOf("reliantunix")!=-1); var is_dec = ((agt.indexOf("dec")!=-1) || (agt.indexOf("osf1")!=-1) || (agt.indexOf("dec_alpha")!=-1) || (agt.indexOf("alphaserver")!=-1) || (agt.indexOf("ultrix")!=-1) || (agt.indexOf("alphastation")!=-1)); var is_sinix = (agt.indexOf("sinix")!=-1); var is_freebsd = (agt.indexOf("freebsd")!=-1); var is_bsd = (agt.indexOf("bsd")!=-1); var is_unix = ((agt.indexOf("x11")!=-1) || is_sun || is_irix || is_hpux || is_sco ||is_unixware || is_mpras || is_reliant || is_dec || is_sinix || is_aix || is_linux || is_bsd || is_freebsd); var is_vms = ((agt.indexOf("vax")!=-1) || (agt.indexOf("openvms")!=-1));You don't need to test for everything. In most cases you'll just be testing for the Netscape or Microsoft browser products, so you can eliminate a lot of the other tests. Keep in mind that WebTV is more of a presence on the Internet than it used to be, and a lot of people use the Opera browser as an alternative to the "big two." You might want to leave those tests in.
Remember to include a <NOSCRIPT>
block in your pages to route non-scriptable browsers elsewhere.