---
sourceDocument: Xanadu API Reference
sourceDocumentLink: https://www.servicenow.com/docs/r/xanadu/api-reference

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    - xanadu

ft:locale :

    - en-US

ft:publication_title :

    - Xanadu API Reference

ft:clusterId :

    - crapiref

bundleId :

    - crapiref

workflow :

    - Creator


---

# Turn on ECMAScript 2021 (ES12) mode for a script

# Turn on ECMAScript 2021 (ES12) mode for a script {#ariaid-title1}

* Release version: Xanadu
* 
* Updated January 30, 2025
* 
* ![](https://www.servicenow.com/docs/portal-asset/ico-clock) 1 minute to read

Use the latest JavaScript features supported with ECMAScript 2021 (ES12) mode in server-side scripts in applications that use ES5 Standards mode or Compatibility mode.

## Before you begin

Role required: delegated developer role or admin

## About this task

Turning on ECMAScript 2021 (ES12) mode for individual scripts is an option for scripts in global or scoped applications configured to use ES5 Standards mode or Compatibility mode. All scripts in applications with the
JavaScript mode set to ECMAScript 2021 (ES12) use ECMAScript 2021 (ES12). Switching the JavaScript mode to ECMAScript 2021 (ES12) for an existing script might change the behavior of the script. For more information, see [Considerations for switching JavaScript modes](https://www.servicenow.com/docs/g~tygOYYV9QPba0hzMbASA "Switching the JavaScript mode for an application or script might change the behavior of existing scripts. Review some examples of behavior changes before switching JavaScript modes or to troubleshoot any issues that you experience after switching.").  
Note:  
Global applications can use ECMAScript 2021 (ES12) mode for individual scripts but not across the application.

## Procedure

1. Navigate to a form with a script field.  
   For example, to open a script include form, navigate to AllSystem DefinitionScript Includes or enter <kbd class="ph userinput">sys_script_include.list</kbd> in the navigation filter.
2. Select an existing script or New.
3. Select Turn on ECMAScript 2021 (ES12) mode.  
   Note:  
   This option is read only for scripts in applications with the JavaScript mode set to ECMAScript 2021 (ES12), which automatically use ECMAScript 2021 (ES12).
4. Select Submit or Update to save your changes.

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