How can I detect kindle fire with javascript?

Question

I'm trying to detect with javascript if my website is running on a kindle fire mobile device. I've tried with navigator.userAgent and navigator.appVersion but I get this results on kindle :

5.0 (Macintosh; U; Intel Mac OS X 10_6_3; en-us) AppleWebKit/533.16 (KHTML, like Gecko) Version/5.0 Safari/533.16

and

Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_3; en-us) AppleWebKit/533.16 (KHTML, like Gecko) Version/5.0 Safari/533.16

What can I use form those strings to know that I'm on a kindle and not on other device?

Answer 1

The User Agent String for Kindle Fire is:

Mozilla/5.0 (Linux; U; Android 2.3.4; en-us; Kindle Fire Build/GINGERBREAD) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1

In Silk mode:

Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_3; en-us; Silk/1.1.0-80) AppleWebKit/533.16 (KHTML, like Gecko) Version/5.0 Safari/533.16 Silk-Accelerated=true

Answer 2

there are two things you should check for 1/ Silk (or Silk-Accelerated) 2/ "Kindle", "KFOT", "KFTT" or others from the table at https://developer.amazon.com/sdk/fire/specifications.html

In Silk or pass-through #1 should give you confirmation, if the web page is being accessed from a WebView then #2 will catch it

Answer 3

One problem is that Amazon changes the strings for every new model. You could check only for Kindle, Silk and KF* but that could potentially lead to false positives. I have altered the code a bit from one of the examples above to make a bit more readable and easy to maintain.

As of November 18, 2015, the below code should work.

Check https://developer.amazon.com/sdk/fire/specifications.html for new models.

This is the code I wrote to redirect people to my game Luna Puma from my website for both Kindle Fire and Android phones:

<script type="text/javascript"> // <![CDATA[

   var ua = navigator.userAgent;

   var kindleStrings = [ 
    "Kindle",
    "Silk",
    "KFTT",
    "KFOT",
    "KFJWA",
    "KFJWI",
    "KFSOWI",
    "KFTHWA",
    "KFTHWI",
    "KFAPWA",
    "KFAPWI",
    "KFASWI",
    "KFTBWI",
    "KFMEWI",
    "KFFOWI",
    "KFSAWA",
    "KFSAWI",
    "KFARWI" ];

   var isKindle = false;

   for (index = 0; index < kindleStrings.length; index++) {
       var matchRegExp = new RegExp (kindleStrings[index]);
       if (matchRegExp.test (ua)) {
           isKindle = true;
           break;
       }
  }

   if (isKindle) { 
        document.location = "amzn://apps/android?asin=B01859LRE0";
   }

   var isAndroid = /Android/i.test (ua);

   if (isAndroid && !isKindle) {
      document.location = "https://play.google.com/store/apps/details?id=com.xanamania.lunapuma";
   } // ]]>

 </script>

Answer 4

in Javascript ,

var ua = navigator.userAgent;
var isKindle = /Kindle/i.test(ua) || /Silk/i.test(ua) || /KFTT/i.test(ua) || /KFOT/i.test(ua) || /KFJWA/i.test(ua) || /KFJWI/i.test(ua) || /KFSOWI/i.test(ua) || /KFTHWA/i.test(ua) || /KFTHWI/i.test(ua) || /KFAPWA/i.test(ua) || /KFAPWI/i.test(ua);
if(isKindle) { 
//Your code here
}

Answer 5

The Silk User-Agent and example JavaScript code to detect Silk can be found on the blog: http://amazonsilk.wordpress.com/useful-bits/silk-user-agent/