Change record values to blank or null with Data Loader

Include NULL values in an update

1. Open Data Loader.
2. Click Settings.
3. Select Insert Null Values. 
4. Click OK.

Note: Due to screen resolution settings, you may not see the OK button. The Enter or Return keys should save the settings if the resolution settings cannot be adjusted.
 

Example

1.  Run Export Data. Make sure to include IDs and any fields that should be changed to NULL.
2.  Delete data contained in the columns that should be returned as NULL (no values).
3.  Save the file as a new .CSV with new name. Don't overwrite the Data Export from step 1 so that you can keep it as a backup of your data.
4.  Run Data Loader Update using new file with Blank values.

Potential Issues

• If the field being updated to NULL is referenced by a workflow or trigger, the update might not be successful. (One workaround you can try is to lower the batch size to 1, then proceed with the update or insert again).
• If the field is Required in your organization, you will not be able to use this method to insert a NULL value. 

See also:
Data Loader behavior with Bulk API enabled using 'Insert null values'


Support videos:
How to Change Record Values to Blank or Null with Data Loader
How to Download and Install Data Loader