How many types of client scripts in service now ?

[PruthwirajS]

Hi Service now family,

Can anyone tell me how many types of client scripts in service now ?

Thanks;

Pruthwiraj 

[Sarthak Kashyap]

Hi @PruthwirajS ,

We have 4 types of client script in Servicenow 

• onLoad(): When the form loads, before user input.
• onSubmit(): When the form is submitted; can validate or cancel submission.
• onChange(): When a specific field’s value changes on a form.
• onCellEdit(): When a cell value is edited in a list.

https://www.servicenow.com/docs/r/api-reference/scripts/client-scripts.html

Please mark my answer correct and helpful if this works for you

Thanks and Regards,

Sarthak

[Deėpak Sharma]

Hi @PruthwirajS 

There are 4 types of Client Scripts in ServiceNow:

1. onLoad()

   Runs when the form is loading, right before the user gets control. Usually used to set initial field visibility, make fields mandatory/read-only, or populate defaults based on existing record data.

2. onChange()

   Fires whenever a specific field value changes on the form. It includes parameters like oldValue, newValue, and isLoading so you can control logic depending on how the field changed.

3. onSubmit()

   Runs when the user clicks Save, Submit, or Update. Best used for final client-side validations (you can stop the save action by returning false).

4. onCellEdit()

   Runs when a user modifies a field directly from a List view (inline editing), rather than inside the form itself.
   
   

For More Information , Please refer this : https://www.servicenow.com/docs/r/xanadu/application-development/scripts/client-scripts.html

Happy to help! If this resolved your issue, kindly mark it as the correct answer ✅  and Helpful and close the thread 🔒 so others can benefit too.

Warm Regards,

Deepak Sharma

Community Rising Star 2025

[NguyenA]

Hi @PruthwirajS ,
There are four types of Client Script: onChange, onLoad, onSubmit, or onCellEdit.

- onLoad(): runs when a form loads and before control is given to the user. Typically used to manipulate a form's appearance or content on the screen

- onSubmit(): runs when a form is saved, updated, or submitted. Typically used for field validation

- onChange(): runs when a particular field value changes. Typically used to respond to field values of interest or modify one field value in response to another

- onCellEdit(): run when a particular field value on a list changes. Typically used to ensure data in a list

[Tanushree Maiti]

Hi @PruthwirajS 

In ServiceNow, there are four main types of Client Scripts. Each type is triggered by a specific user action or browser-side event and is used to enhance the user experience on forms and lists.

1. onLoad()

Trigger: Executes when a form finishes loading in the browser.

Common Use Cases:

• Setting default field values.
• Showing or hiding fields and sections.
• Making fields read-only or mandatory based on conditions such as user roles.
• Initializing form behavior when the record is opened.

1. onChange()

Trigger: Executes when the value of a specified field changes.

Common Use Cases:

• Auto-populating related fields.
• Displaying validation messages or alerts.
• Dynamically showing, hiding, enabling, or disabling fields based on user selections.
• Performing client-side validation.

Note: The isLoading parameter is commonly used to prevent the script from running while the form is still loading.

1. onSubmit()

Trigger: Executes when a user attempts to save, submit, or update a form.

Common Use Cases:

• Performing final validation checks before data is sent to the server.
• Ensuring required business conditions are met.
• Displaying confirmation messages or preventing invalid submissions.

Note: Returning false from an onSubmit Client Script prevents the form from being submitted.

1. onCellEdit()

Trigger: Executes when a user edits a field directly within a list view using inline editing.

Common Use Cases:

• Validating changes made from a list.
• Enforcing data integrity rules during inline edits.
• Controlling or restricting bulk updates.

Note: This script type uses parameters such as sysIDs, table, oldValues, newValue, and a callback function to validate and approve or reject the change.