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Is Your Web Browser Java Enabled?

Although most current web browsers are capable of running Java applets (programs), this support can be disabled. Below are some ways to tell if your browser is Java enabled.

1. HTML Trick

The HTML test below should indicate if your browser currently supports Java.

A browser that supports Java displays: "This web browser can indeed run Java applets" and it should look like:

sample

A browser that does not support Java displays: "This web browser can NOT run Java applets" and should look like:

sample

How this works: Applets are included in a web page with the HTML APPLET tag. Web browsers that do not support Java (either because they can not or because a configuration option has been set to disable Java) are supposed to display text inside the <APPLET> tag. The above test is coded using HTML that looks like:  
       This web browser can <applet ...>NOT</applet> run Java applets

If the applet can run, it displays the word "indeed" in blue. If it can not run, the web browser is supposed to display the word "NOT". 

Note that Firefox 1.0 with Java and the Adblock extension wraps the display on two lines (seems to be a Firefox bug). Firefox 1.0 without Java and with no extensions, does not correctly display the word "NOT" (another bug). Instead it displays a green jigsaw puzzle piece.

2. Manually Checking

Firefox 3 users can check if Java is enabled with Tools -> Options -> Content Panel. There is a checkbox to Enable Java.
For more about Java and Firefox see support.mozilla.com/en-US/kb/Java.

Firefox 2 users can check if Java is enabled with Tools -> Options -> Content panel. There is a checkbox to Enable Java.

Firefox v1.0.4 users can manually check with Tools -> Options -> Web features -> checkbox for "Enable Java". Another approach is to enter about:plugins in the address bar. If Java is installed there will be multiple entries labeled "Java Plug-in".

3. From JavaScript

JavaScript is a programming language run by your web browser. If your browser supports JavaScript and this support is enabled, then we can use a JavaScript function to report on whether Java is enabled or not. This is what JavaScript reports about your browser:

This is done with a JavaScript command much like:  
   document.write("Is Java enabled? " + navigator.javaEnabled() );

Note: I've been told more than once that under Windows XP SP2 with IE6 that this test reports "True" even if Java is not installed. I haven't confirmed this myself. I did notice that on an XP system that just had Sun's Java un-installed (prior to installing a newer version), this reported "True" because it fell back to using Microsoft's Java. I've also been told that on Windows ME, IE 5.5 falsely reports Java as "true" when there is no Java instaled.

4. From JavaScript Again

A reader of this page suggested this technique (thanks Ed). If Java is enabled it should say "I'm here" in between the arrows below. 

This is done using the following JavaScript and Java commands:
     <script> document.write(new java.lang.String("I'm here")); </script>

The bad news is that this does not work with Internet Explorer v6 (all patches as of May 2005, Windows 2000). It did work, however, with Firefox v1.0.4. (Windows 2000)

If Java is installed, but not enabled, Sun has instructions to Enable the JRE through your Web browser and to Enable the JRE through the "Java™ Plug-in Control Panel".  Sun also has a Test Java Virtual Machine web page that did not work for me. See the Installing page for more on this.