When it comes to subscriber fields, you have options.
By default, we only include first name and email address on your subscribers’ profiles, but it’s easy to create additional subscriber fields. (And yes, they can be added to your forms and landing pages.)
At ConvertKit, we refer to these as custom fields, and they can be used to store other types of information about your subscribers (such as their last name, phone number, favorite color, and so on).
There are several ways to add new custom fields to your ConvertKit account. The first way is to do so directly while editing a form or landing page. Or, you can add them while editing a Visual Automation.
Or, you can create as many custom fields as you want right on your subscriber profiles. The steps below explain that process!
1. In your ConvertKit account, navigate to any subscriber’s profile
NOTE: Don't have any subscribers yet? No worries — just add yourself to your list as a single subscriber following this tutorial, then come back to this article. (You can always delete yourself from your list later, if you want!)
2. Under the subscriber’s first name field, click "+ Add a new field"
3. Enter your new custom field’s name & value
After clicking "+ Add a new field", you'll see two text boxes: one for field name, and one for field value.
Field name: What you are naming (or labelling) this field, such as "Last Name". This name is internal for your reference.
Field value: What information should be saved in this field for this subscriber, such as their actual last name. If you don't have specific information to add to this individual subscriber, you can leave the field value blank.
4. Click ‘Update Subscriber’
When you’re done, click the red ‘Update Subscriber’ button to save your changes.
Note: Even though you added the custom field on one specific subscriber's profile, the field will now exist across your account, for every subscriber.
Repeat the process above for each custom field you want to add!
Once your custom fields are all created, you can add them to your forms and landing pages, set up automations based on their values, and more.
Considerations for custom fields
Here are some considerations to keep in mind when setting up your custom fields:
Our custom fields are not made for paragraphs.
As a result, our forms are not intended to be used as contact forms. If you need a contact form, we’d recommend checking out our Integrations page to find a suitable 3rd party form builder that integrates with ConvertKit, instead of using one of our forms directly.
All custom field data is stored as plain text.
For example, while you can store dates in custom fields, ConvertKit will not detect those values as dates, nor be able to perform date-based logic on their values. The date values will simply be stored as plain text.
However, just because our app can't detect those values doesn't mean you can't interact with them as values.
To learn more, check out this article on advanced Liquid logic.
Developer Note on limitations of custom fields
This section will not be applicable for most users, but if you are a developer and accessing the ConvertKit API you should know about some of the limitations.
Each ConvertKit account is limited to 140 custom fields. If you try and update more than 140 fields you will receive a response of '400'. This is fairly important so I'm going to say it again in a calloutbox:
Every custom field is available for every subscriber on your list.
Once you add a custom field to one subscriber’s profile, that custom field will become available for all of your subscribers, and will show on each of their profiles (even if its value is blank).