FAQ

QZ Tray uses websockets to communicate to the browser without the use of NPAPI. On the contrary, in order for QZ Print (formerly "jzebra") to work, NPAPI must be enabled in the web browser. This is a concern because Google (Chrome) has disabled NPAPI in Chrome 32 and higher. NPAPI was permanently blocked in Chrome in September 2015. NPAPI will be permanently blocked in Firefox in January 2017.
For API changes, see QZ Print vs QZ Tray.

Java Version

Product Minimum Version

QZ Tray Java 7 / OpenJDK 1.7

QZ Print Java 6 / OpenJDK 1.6
Operating System

Operating System Minimum Version

Apple OS X OS X 10.7 Lion or higher*

Microsoft Windows Windows XP or higher*

Linux Ubuntu 12.04 Precise or higher

*Safari 5.1.7 is bundled with Lion but is not supported. Alternate browser required. *Windows XP requires manual certificate installation. Will prompt at install time.
Web Browser

Web Browser Minimum Version

Safari Safari 6.0.3 or higher

Firefox Firefox 31 or higher

Chrome Chrome 31 or higher

Internet Explorer IE 10 or higher

Microsoft Edge 20.x or higher

QZ Tray is free. Organizations wishing to print silently are required to purchase a certificate from QZ Industries, LLC. Pricing options can be found on QZ's homepage at https://qz.io.

The premium version of QZ Tray provides you the ability to generate a certificate to print silently. Without this certificate, you will be given a warning on each print that an untrusted website is requesting to access local resources. This certificate is valid for one year and must be renewed to continue silent printing. Additionally, there are no client or user limitations; this certificate is valid for as many client/users as you need.
The purchase of the premium version also provides technical support for one year. The Technical Support Team of QZ Industries, LLC will work diligently to help you integrate QZ Tray into your environment. All questions are promised to be answered as fast as possible (usually well within a 24-hour period).

Yes, installation of a new version will succeed even if an older version is present and/or running.

Yes, QZ Tray currently supports web pages hosted with 2048-bit SSL encryption using a just-in-time certificate installation method (all OSs require the certificate to be installed and trusted locally by your PC). Questions or concerns about the certificate installation can be directed at https://qz.io/support.

If the browser console says Invalid JSON, try changing your HTTP headers in the sign-message example to use text/plain instead of application/json. In PHP, this is done via:
```
- header('Content-Type: application/json');
+ header('Content-Type: text/plain');
```

Note: This technique will vary depending on the server-side language being used.

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Product	Minimum Version
QZ Tray	Java 7 / OpenJDK 1.7
QZ Print	Java 6 / OpenJDK 1.6