---
sourceDocument: Yokohama Build or modify applications
sourceDocumentLink: https://servicenow-prod.fluidtopics.net/r/yokohama/application-development

 Release :

    - yokohama

ft:locale :

    - en-US

ft:publication_title :

    - Yokohama Build or modify applications

ft:clusterId :

    - cadev

bundleId :

    - cadev

workflow :

    - Development, Data, and Analytics


---

# JavaScript debug window

# JavaScript debug window {#ariaid-title1}

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

The JavaScript debug window appears in a bottom pane of the user interface when an
administrator turns on debugging.  
Note:  
The JavaScript debug window is not supported with Next Experience in Utah. For more information about supported features in Next Experience, see [Considerations for activating Next
Experience](https://www.servicenow.com/docs/access?context=next-experience-adoption-paths&version=yokohama&pubname=yokohama-platform-user-interface&ft:locale=en-US).

Use the debug window to access these tools.

* JavaScript Log: JavaScript that runs on the browser, such as client scripts, can include a call to jslog() to send information to the JavaScript log.
* Field Watcher: a tool that tracks and displays all actions that the system performs on a selected form field.

Figure 1. JavaScript debug window

## Using the JavaScript debug window {#ariaid-title2}

The JavaScript debug window enables access to the JavaScript Log and the Field
Watcher tools.

### Before you begin

Role required: admin

### About this task

The steps to access the JavaScript debug window depend on which UI version you are
using.  
Note:  
The JavaScript debug window is not supported with Next Experience in Utah. For more information about supported features in Next Experience, see [Considerations for activating Next Experience](https://www.servicenow.com/docs/access?context=next-experience-adoption-paths&version=yokohama&pubname=yokohama-platform-user-interface&ft:locale=en-US).

### Procedure

1. Open the JavaScript debug window by navigating to the appropriate location for your version of the UI.  

   |-|-|
   | Core UI | 1. Click the gear icon in the banner frame. 2. Click the Developer section. 3. Toggle the JavaScript Log and Field Watcher switch. {#t_UsingTheJavaScriptDebugWindow__ol_rf2_2dq_ms} |
   | UI15 | 1. Click the gear icon in the banner frame. 2. Click JavaScript Log and Field Watcher. {#t_UsingTheJavaScriptDebugWindow__ol_em3_kdq_ms} |
   | UI11 | Click the debug icon (![The debug icon]()) in the banner frame. |
   [ ]

   {#t_UsingTheJavaScriptDebugWindow__simpletable_HowToOpenJavaScriptLogAndFieldWatcherInDifferentUIs}  
   The JavaScript debug window re-opens at the bottom of the screen. The tab that is currently active in the window is the last tab that was active when the window was closed.
2. Click a tab to use one of the debug window features.
   * JavaScript Log
   * Field Watcher
**Related topics**   

* [Writing to the debug log](https://www.servicenow.com/docs/access?context=c_WritingToTheDebugLog&version=yokohama&pubname=yokohama-api-reference&ft:locale=en-US)
* [Field watcher](https://www.servicenow.com/docs/access?context=c_FieldWatcher&version=yokohama&pubname=yokohama-api-reference&ft:locale=en-US)