Connect Ninja Forms to MailerLite (Free Plugin)

Connect Ninja Forms to MailerLite

Connect Ninja Forms to MailerLite with a form action. The free ClickSyncr for MailerLite plugin registers a MailerLite (ClickSyncr) action under Core Actions: save one API key in Ninja Forms settings, add the action to a form, pick a group and map fields with merge tags.

Before you begin

You need three things: the ClickSyncr for MailerLite plugin activated, Ninja Forms active, and a MailerLite account (the free tier is fine, with permission to create an API token). Ninja Forms uses one global API key, then an action added to each form that should sync.

Get your MailerLite API key

Log in to MailerLite and go to Integrations → API (dashboard.mailerlite.com/integrations/api).
Generate a new token and give it a recognisable name such as WordPress ClickSyncr.
Copy it immediately: MailerLite shows the full token only once. If you lose it, generate another.

Treat the token like a password. Anyone holding it can read and modify your MailerLite subscribers.

Ninja Forms setup, step by step

Save your API key in Ninja Forms settings. Go to Ninja Forms → Settings and scroll to the MailerLite (ClickSyncr) panel. Paste the key and save. If you already saved a key in Fluent Forms, leave this empty; the shared key is used automatically.

The MailerLite API key panel in Ninja Forms settings.
Open the form and add the action. Edit your form, switch to Emails & Actions, click the large plus button, and pick MailerLite (ClickSyncr) from Core Actions.

The action drawer. MailerLite (ClickSyncr) sits under Core Actions.
Choose the group and map fields. Pick the MailerLite group, fill in Email Address (required) and any other fields. The boxes accept merge tags: click the small field icon at the right of a box to insert the right form field rather than typing it.

Action settings: group picker plus a merge-tag box per MailerLite field.
Publish the form. Publish stores the action and the next submission syncs.

The nine MailerLite fields

Every builder maps the same nine standard MailerLite fields, and any custom fields in your account appear in the list automatically. Only Email is mandatory; an unmapped field is simply skipped and never overwrites existing subscriber data with a blank value. If MailerLite rejects one value’s type, that single field is dropped and the subscriber still syncs.

Field	MailerLite key	Notes
Email	`email`	Required. The subscriber identifier.
Name	`name`	First name.
Last name	`last_name`
Phone	`phone`
Company	`company`
City	`city`
Country	`country`
State	`state`
Zip	`z_i_p`	MailerLite’s key really is z_i_p.

Verify the sync

Submit the form on the front end (not the admin preview) with a test address you can recognise, filling every mapped field. In MailerLite, open Subscribers and confirm the subscriber exists, sits in the group you selected, and carries the mapped values. That one minute catches almost every configuration mistake.

Troubleshooting

Symptom	Cause and fix
The group dropdown is empty	The key is missing, mistyped, or was revoked in MailerLite. Re-paste it and reconnect. A key with a trailing space is the classic culprit.
Submissions do not appear in MailerLite	Nine times out of ten the Email field is not mapped. It is the one required mapping. Fix it, then submit a fresh test.
The action shows no groups	No key is saved in Ninja Forms settings and no shared key exists from Fluent Forms. Save the key in either place, then reopen the action.
The subscriber syncs but a field is empty	Either that field is unmapped, or it was blank on the submission. Empty values are skipped so they never wipe existing MailerLite data.
One field never arrives, the rest do	MailerLite rejected that value’s type, for example letters in a number field. The plugin drops just the offending field and syncs the rest.

Does every Ninja Forms form sync automatically?

No. Only forms where you add the MailerLite (ClickSyncr) action sync, so you stay in control per form.

Can I type values instead of merge tags?

You can, but the field icon beside each box inserts the correct merge tag and avoids typos.

Other form builders

ClickSyncr for MailerLite also connects Contact Form 7 · WPForms · Gravity Forms · Fluent Forms · Formidable Forms · Forminator. Overview, features and pricing: MailerLite integration for WordPress. Browse all ClickSyncr integrations.

“MailerLite” is a trademark of its respective owner. ClickSyncr for MailerLite is an independent integration and is not affiliated with, endorsed by, or sponsored by MailerLite.

Connect Ninja Forms. Send every lead to MailerLite.

Connect, map, test, publish.

Prepare the fields

Connect the account

Choose the destination

Match the fields

Submit and verify