Google Sheets to MailerLite Subscriber Synchronization - n8n Workflow

• Marketing managers needing reliable data synchronization between spreadsheets and their Email Service Provider (ESP).


• Technical users looking for efficient n8n templates for CRM and list management integration.


• Anyone requiring a robust n8n workflow solution to manage mailing lists without creating duplicate entries.


• Users transitioning data manually who want to automate the process using n8n.

This essential n8n workflow provides a powerful, reliable method for transferring prospect or customer data stored in Google Sheets directly into MailerLite. The core value of this n8n automation lies in its built-in deduplication mechanism. By first attempting to retrieve the subscriber using the MailerLite n8n node, the flow intelligently routes existing subscribers to an exit point while only allowing truly new contacts to proceed to the creation step. This design ensures clean data management, prevents list clutter, and maximizes the efficiency of your email marketing campaigns. Implementing this n8n workflow saves significant time compared to manual exports and imports, making it one of the most useful n8n templates for CRM data management.

This automation starts via a manual n8n trigger for immediate execution:

1. Trigger & Data Retrieval: The n8n workflow starts with the Manual Trigger n8n trigger, allowing the user to initiate the sync on demand. Immediately after, the Google Sheets n8n node retrieves all specified rows of subscriber data, including crucial fields like 'Email' and 'group_id'.


2. Deduplication Check: The data then flows into the MailerLite n8n node, configured to perform a 'Get a subscriber' operation using the email address. This n8n node is set to continue execution on error.


3. Existing User Route (Success Branch): If the subscriber is found in MailerLite (successful retrieval), the item is directed to the 'End workflow' n8n node, which gracefully terminates the process for that specific contact, ensuring no duplicate record is created.


4. New User Route (Error Branch): If the MailerLite n8n node fails to find a subscriber (meaning they are new), the workflow uses the error output to proceed to the final action.


5. Creation and Group Assignment: The final n8n node, an HTTP Request, posts the new subscriber data—including custom fields like name, company, and country—to the MailerLite API. It ensures the new contact is immediately assigned to the specified group, completing the synchronization for the new contact using the n8n workflow logic.

To deploy and utilize this n8n workflow, follow these steps:

1. Import the n8n template: Copy the provided JSON code and import it into your self-hosted or cloud n8n instance.


2. Google Sheets Setup: You need valid Google Sheets credentials (with Drive scope enabled). Configure the 'Get row(s) in sheet' n8n node by selecting your specific spreadsheet and sheet name. Ensure your sheet contains the mandatory columns: Email, firstname, lastname, Company, Country, and group_id.


3. MailerLite API Credentials: Set up your MailerLite API credentials. These credentials must be attached to two separate n8n nodes: the 'Get a subscriber' MailerLite n8n node and the final 'Create subscriber and assign to group' HTTP Request n8n node (used for authentication).


4. Testing: Run the n8n workflow manually using the 'Start Workflow' n8n trigger to verify that data is correctly fetched and synchronized without duplicates.

This n8n workflow utilizes several key n8n nodes for data flow control and external API interaction:

Start Workflow (Manual Trigger n8n trigger):
Function: Manually initiates the entire n8n workflow run.
Key Configuration: Simple trigger for testing and on-demand execution.
Google Sheets (Get row(s) in sheet):
Function: Acts as the primary data source, pulling all necessary contact details from the specified Google Sheet.
Key Configuration: Requires selecting the Document ID and Sheet Name (e.g., gid=0).
MailerLite (Get a subscriber n8n node):
Function: Checks for the existence of the subscriber using the email address provided by the Google Sheets n8n node.
Key Configuration: subscriberId set to ={{ $json.Email }}; onError set to continueErrorOutput, which is crucial for routing new subscribers correctly.
End workflow (NoOp n8n node):
Function: Provides a clean exit path for data items representing subscribers already existing in MailerLite, successfully implementing the deduplication logic of the n8n workflow.
HTTP Request (Create subscriber and assign to group n8n node):
Function: Handles the API call to MailerLite to create a new subscriber and assign them to a specified group, executed only for items that failed the previous existence check.
Key Configuration: Method set to POST, URL targeting the MailerLite subscribers API, and JSON Body dynamically mapping data fields from the Google Sheets n8n node output (e.g., "email": "{{ $json.Email }}").