bulkUpdate( )

Updates a number of items in a collection.

The bulkUpdate() function returns a Promise that resolves after the items have been updated in the specified collection. The Promise is rejected if the current user does not have update permissions for the collection. Items are skipped if they include an _id property whose value does not match an existing ID in the collection. Meaning, bulkUpdate() cannot add new items into the collection.

Calling the bulkUpdate() function triggers the beforeUpdate() and afterUpdate() hooks for each item that is updated if the hooks have been defined.

The bulkUpdate() function compares the _id property of the specified items with the _id property values of the items in the specified collection.

Warning: If an existing item in the specified collection matches the _id of the specified item, bulkUpdate replaces the existing item's property values with the ones in the specified item. If the existing item had properties with values and those properties were not included in the specified item, the values in those properties are lost. The item's _updatedDate property is also updated to the current date.

Any valid JavaScript object can be used as a property value. The bulkUpdate() function maintains the structure of the specified object. For example, objects that contain nested objects, Arrays, or Arrays with nested objects are all added to the collection as defined.

Use the options parameter to run bulkUpdate() from backend code without checking for permissions or without its registered hooks.

When updating items in a collection that has a reference field, set the values of the reference field to the referenced item's _id value or the entire referenced item object.

The maximum size of an item that you can update in a collection is 500kb.


  • Bulk operations are limited to 1000 items per function call.
  • The bulkUpdate() function is not supported for Single Item Collections.
  • The bulkUpdate() function does not support multi-reference fields. For multi-reference fields, use replaceReferences() or insertReference().
  • Translatable collections do not allow insertion and modification of items when working in a non-primary language. For example, if a collection's primary language is English, and the site visitor is viewing the site in French, calling bulkUpdate() will fail and issue an error.
Method Declaration
Method Parameters

The ID of the collection that contains the item to update.

To find your collectionId, select the Databases tab in the Velo Sidebar. Hover over your collection, click the three dots, and select Edit Settings.


The items to update.

The array must contain at least one item. Passing an empty array returns an error.


An object containing options to use when processing this operation.

Return Type:Promise<WixDataBulkResult>
Was this helpful?