How to update custom fields for many contacts at once - Jobin documentation

To update custom fields for many contacts at once, select the contacts, open the bulk actions, and choose Manage records > Add custom fields.

What this gets you

You update hundreds of contacts in one action instead of editing each one.
Your data stays consistent, because everyone gets the same values.

Before you start

Select the contacts yourself. Selecting everything isn’t supported for this action.

Steps

Open Contacts and select the contacts.
Open the bulk actions and choose Add custom fields under Manage records.
Prepare one or more field-and-value pairs.
Check how many contacts will be updated.
Apply the values to all selected contacts.

Ideas to get more from it

After an event or a screening round, mark all attendees with the same value.
Set a field on everyone in a segment, then filter on that field later.