How do I use a custom PAC file to forward traffic to ZIA?

How do I use a custom PAC file to forward traffic to ZIA?

The ZIA admin portal can host your custom PAC file(s). When you add a PAC file to the admin portal, you can check its syntax and correct any errors before you save it.


  • Ensure that you review the best practices.
  • Test the newly edited or created PAC file on a local machine before production deployment.

Adding a Custom PAC File to the Zscaler Admin Portal

To add a PAC file to the service, log in and do the following:

  1. Go to Administration > Resources > Hosted PAC Files.
    The page lists the default PAC files and any other custom files that were uploaded to the service.
  2. Click Add PAC File.
  3. In the Add PAC File window, complete the following:
    • Description: Enter a description for the PAC file. The description and the name cannot exceed 255 characters.
    • PAC File Name: Enter a name for the PAC file.
    • Domain: This field displays the domain name that your organization provided when it first registered. If there are multiple domain names, select the domain to which the PAC file applies.
    • Obfuscate URL: Enable to obfuscate the PAC file URL. Highly recommended.

If you are editing a PAC file, enabling Obfuscate URL changes the Hosted URL. The new Hosted URL must be redistributed to your users. Users using the old Hosted URL will be served by the default proxy PAC file instead of the intended custom PAC file. To ensure users are using the new Hosted URL, follow these instructions. 

  1. Click Verify to check the syntax in the PAC file. One of the following error messages displays:
    • If the PAC file has errors, the service displays:

You can correct the PAC file and click Verify again to ensure that there are no errors.

  • If the PAC file has no syntax errors, the service displays:

  1. Click Save and activate the change.

Next Steps

After adding the custom PAC file to the ZIA admin portal, you must do the following:

  1. Distribute the PAC file URL to your users.
  2. Review the firewall requirements, and ensure that you have made the necessary configuration changes.
  1. Edit the PAC file of which you want to obfuscate the URL.
  2. In the Edit PAC File window, copy the PAC file content.
  3. Close the window.
  4. Click Add PAC File.
  5. Enter the information and paste the content from the old PAC file.
  6. Ensure that Obfuscate URL is enabled.
  7. Click Save and activate the change.
  8. Distribute the new PAC file URL to your users.