Frequently Asked Questions

1. What is Javascript?
Javascript is one of the most popular scripting language in the web today that has existed for 18 years. Almost every modern website uses Javascript. Even Windows 8 App can be develop using Javascript
2. Do I need to know Javascript?

Javascript knowledge is not required. Our script editor comes with AutoCompletion, which means you can browse through most of the syntax and parameters directly in the editor

2. Does LazJS have to be installed on all computers?

Yes, LazJS runs on a JavaScript engine which needs to be deployed to all computers running it.

To simplified deployment, you can deploy the required files to a network location and allows the client machine to load the plugin from the network location. This will require a modification to Revit.exe.config in the program files directory (Refer to this post).

You can also deploy the files to the user application data directory which will not require administration right.

Contact us at if you want to know more.

1. Where can I purchase LazJS?
Visit our Purchasing FAQ page at for more information.
2. How does licensing works?
Visit our Licensing FAQ page at for more information.
1. What makes it different than VSTA or Visual Studio?
Javascript does not need to be compiled. Hence, it can be executed directly.
2. How is the performance compared to other scripting languages?
We have run a comparison with almost every scripting languages. Javascript outperforms IronPython by 10x and more. On the other hand, JScript and VBScript provides a comparable performance. We'll post a whitepaper soon.
3. How is the performance compared to VSTA or Visual Studio?
Native VSTA or Visual Studio application performs the best but if object creation is involved, e.g. new Class(), javascript will always faster because there is no overhead in object creation.
4. Does it slows Revit down?
Javascript Engine used in LazJS is extremely fast because all script is tranlated to Machine code directly. For example, calculating a parameter value for 150 doors took 50ms and updating 150 doors took 150ms. Most of the time is taken for Revit to update the parameter.
5. Should I learn more on Javascript?
  • Javascript syntax is very similar to C# so it should make the transition easier if you decide to move to Visual Studio in the future.
  • Javascript can be used in other application such as AutoCAD