Method 1 of 3: Allow Java content on a website
Step 1. Open Firefox
It's the orange fox icon around a blue globe.
Step 2. Go to a site that uses Java
If there is a particular site you want to access that uses Java, go to that site.
Step 3. Wait for a Java command prompt to appear
You should see a link in the middle of the page (or in the Java content area) that says "Enable Java" or something similar.
Step 4. Click the Activate Java link
This option should be on or near the Java content you want to load.
If you see a message that says Java "is not supported", "is disabled", "is not installed" or something like that instead of "Enable Java", it means you cannot run the site in question on Firefox
Step 5. Click Authorize Now
This command prompt should appear at the top left of the browser window. Click on it to reload the website with Java content enabled.
- You can also click Activate and remember to place the site on the "Allowed" list on Firefox.
Method 2 of 3: Enable all Java content
Step 1. Know the limitations of this method
For security reasons, recent versions of Firefox do not support Java, as do future versions. To enable Java content, you will need to install an older 32-bit version of the browser and then manually add the Java plug-in. This is possible on Windows computers, however Firefox for Mac defaults to 64-bit, making it impossible to install Java for the browser on a Mac.
- Closing and reopening Firefox may initiate the browser update, which will render Java unusable.
- Using an older version of Firefox puts you at risk of computer viruses or malware.
- You should never update your old version of Firefox, as you may block Java support.
Step 2. Open the Java website
Go to in a browser. Before you can install Java as an add-on in Firefox, you will need to download and install it.
Step 3. Download and install Java
Here's how to do it:
- click on Java free download;
- select Accept and start the free download;
- double click on the downloaded file;
- choose Yes at the command prompt;
- click on To install at the bottom of the Java window.
Step 4. Open the Firefox 51 download page
Go to this page in a browser. This is where you can download the latest version of Firefox that supports Java.
Step 5. Choose a 32-bit link
Click on firefox-51.0b9.win32.sdk.zip at the bottom of the list of links on this page.
Step 6. Open the downloaded ZIP folder
Double click on the ZIP folder to open it.
Step 7. Extract the contents of the ZIP folder
- click on the tab Extract at the top of the window;
- select Extract all in the displayed toolbar;
- choose Extract at the bottom of the pop-up window.
Step 8. Open the extracted folder
Double click on the folder firefox-51.0b9.win32.sdk (not the ZIP folder) to open it.
Step 9. Open the firefox-sdk folder
This is the only folder in the window.
Step 10. Open the bin folder
Double-click on this folder, which is located at the top of the window.
Step 11. Double-click on the Firefox application icon
You'll find it in the middle of the page. Double-click on it to open the Firefox 51 application.
Step 12. Turn off automatic updates
Type about: config in the Firefox address bar, press Enter, then do the following:
- select Accept the risk and continue at the command prompt;
- click on the search bar at the top of the page;
- type app.update.auto;
- double click app.update.auto to change its value from "true" to "false".
- be sure to click Not now Where Ask later if you are asked to install an update.
Step 13. Click ☰
This button is located at the top right of the window and displays a menu.
Step 14. Select Add-ons
This puzzle icon can be found in the menu. Click on it to open the Add-ons page.
Step 15. Go to the Extensions tab
This tab is on the left of the page.
Step 16. Look for the Java (TM) Platform option
Usually it is near the bottom of the page.
Step 17. Click the Ask drop-down field to activate
You'll find it to the right of the Java (TM) Platform heading. Click on it to display a drop-down menu.
Step 18. Choose Always Activate
This option is in the drop-down menu. It allows Java to be enabled for all websites you visit in this version of Firefox, however you should be careful not to update your browser.
If you accidentally updated Firefox or if an update was accidentally installed, you can reinstall Firefox 51 by deleting the firefox-51.0b9.win32.sdk folder (not the ZIP version), opening the ZIP folder of the same name, extracting it again, then reopening the Firefox 51 application from the bin folder
Step 1. Open Firefox
The Firefox icon looks like an orange fox around a blue globe.
Step 2. Go to the configuration page
Type about: config then press Enter.
Step 3. Click Accept Risk and Continue
It's the blue button in the middle of the page.
If you see false under the value header, go to the next step