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

 Release :

    - australia

ft:locale :

    - en-US

ft:publication_title :

    - Australia API Reference

ft:clusterId :

    - crapiref

bundleId :

    - crapiref

workflow :

    - Creator


---

# Set the JavaScript mode for an application

# Set the JavaScript mode for an application {#ariaid-title1}

* Release version: Australia
* 
* Updated March 12, 2026
* 
* ![](https://www.servicenow.com/docs/portal-asset/ico-clock) 1 minute to read

Configure which ECMAScript features can be used in an application by selecting the JavaScript mode.

## Before you begin

Role required: delegated developer role granting full access or admin

## About this task

The JavaScript mode is a design and runtime setting for custom applications and scripts. To support existing server-side scripts and new scripts developed to the ECMAScript 2021 standard, the JavaScript engine has three
modes: ECMAScript 2021 (ES12), ES5 Standards, and Compatibility. For more information about each mode, see [JavaScript modes](https://www.servicenow.com/docs/DZib8zAWKTVfBrZbTNxVKA "JavaScript mode is a design and runtime setting for custom applications and scripts. To support existing server-side scripts and new scripts developed to the ECMAScript 2021 standard, the JavaScript engine has three modes: ECMAScript 2021 (ES12), ES5 Standards, and Compatibility.").

For applications that use ES5 Standards or Compatibility mode, you can also turn on ECMAScript 2021 (ES12) for individual scripts in the application. For more information, see [Turn on ECMAScript 2021 (ES12) mode for a script](https://www.servicenow.com/docs/X4tZiIaqIxaWT62wYIqrug "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.").  
Note:  
Switching the JavaScript mode to ECMAScript 2021 (ES12) for an existing application might change the behavior of its scripts. For more information, see [Considerations for switching JavaScript modes](https://www.servicenow.com/docs/~~lZ54wrv03N6rdsg7Sn9Q "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.").

## Procedure

1. In the application navigator, enter <kbd class="ph userinput">sys_app.list</kbd>.
2. Select an application.
3. In the JavaScript Mode field, select the mode to use.
   * ECMAScript 2021 (ES12): Supports a subset of ECMAScript 2021 (ES12) and ECMAScript 2022 (ES13) syntax and features.
   * ES5 Standards Mode: Supports ECMAScript5 syntax and features.
   * Compatibility Mode: Used for all scripts developed prior to the addition of ES5 Standards mode.
   {#set-javascript-mode-application__choices_xvq_f4b_hbc}
4. Select Update.
**Related topics**   

* [Modify an app's settings in ServiceNow Studio](https://www.servicenow.com/docs/access?context=modify-an-apps-settings-in-servicenow-studio&version=australia&pubname=australia-application-development&ft:locale=en-US)