How to Compare Google Sheets and HubSpot Contact Lists with N8n

Workflow > Add Node > Google Sheets

Connect Google Sheets

Add your Google Sheets account to N8n and authorize access. You'll need the Sheet ID from your URL to target the right document.

1. 1Click the + button to add a new node
2. 2Search for 'Google Sheets' and select it
3. 3Choose 'Read' operation from the dropdown
4. 4Click 'Create New' next to Credential for Google Sheets API

Google Sheets Node > Parameters

Configure Sheet Data Source

Point N8n to your contacts spreadsheet and specify which columns contain the contact data. The Sheet ID comes from the URL between /d/ and /edit.

1. 1Paste your Google Sheet ID into the Document field
2. 2Enter your sheet name (usually 'Sheet1' or 'Contacts')
3. 3Set Range to 'A:Z' to capture all contact columns
4. 4Toggle 'Has Header Row' to true

Workflow > Add Node > HubSpot > Contact

Add HubSpot Connection

Connect to HubSpot's API to fetch your CRM contact list. You'll need a private app token with contacts read permission.

1. 1Add a new node and select 'HubSpot'
2. 2Choose 'Contact' as the resource
3. 3Select 'Get All' operation
4. 4Create new HubSpot credential with your private app token

HubSpot Node > Additional Options

Set HubSpot Contact Properties

Specify which contact fields to retrieve from HubSpot. Include at minimum email, first name, and last name for comparison.

1. 1Click 'Add Option' in the HubSpot node
2. 2Select 'Properties to Return'
3. 3Enter 'email,firstname,lastname,phone,company' in the field
4. 4Set limit to 500 to handle larger contact lists

Workflow > Add Node > Code

Add Code Node for Comparison Logic

Create a JavaScript function to compare both contact lists and identify missing contacts. This node will receive data from both previous nodes.

1. 1Add a new 'Code' node after both data sources
2. 2Select 'Run Once for All Items' mode
3. 3Connect both Google Sheets and HubSpot nodes as inputs
4. 4Name the node 'Contact Comparison'

Drop this into an n8n Code node.

// Normalize emails for better matching
const normalizeEmail = (email) => {
  return email.toLowerCase().trim().replace(/\+.*@/, '@');

// Normalize emails for better matching
const normalizeEmail = (email) => {
  return email.toLowerCase().trim().replace(/\+.*@/, '@');
};

// Find contacts in A but not in B
const findMissing = (listA, listB, keyField) => {
  const bEmails = new Set(listB.map(item => normalizeEmail(item[keyField])));
  return listA.filter(item => !bEmails.has(normalizeEmail(item[keyField])));
};

Code Node > JavaScript Code Editor

Write Comparison JavaScript

Add code that compares email addresses between both lists and identifies contacts missing from either system. The code accesses input data from both connected nodes.

1. 1Clear the default code in the JavaScript editor
2. 2Paste the comparison logic that iterates through both contact arrays
3. 3Add logic to normalize email addresses to lowercase for comparison
4. 4Return arrays of missing contacts from each system

Drop this into an n8n Code node.

// Normalize emails for better matching
const normalizeEmail = (email) => {
  return email.toLowerCase().trim().replace(/\+.*@/, '@');

// Normalize emails for better matching
const normalizeEmail = (email) => {
  return email.toLowerCase().trim().replace(/\+.*@/, '@');
};

// Find contacts in A but not in B
const findMissing = (listA, listB, keyField) => {
  const bEmails = new Set(listB.map(item => normalizeEmail(item[keyField])));
  return listA.filter(item => !bEmails.has(normalizeEmail(item[keyField])));
};

Workflow > Add Node > Split Out

Add Split Node for Results

Split the comparison results into separate paths so you can handle missing contacts from each system differently. This creates two workflow branches.

1. 1Add a 'Split In Batches' node after the Code node
2. 2Change the operation to 'Split Out' instead
3. 3Set the field name to split on (like 'source_system')
4. 4Connect the output to two different paths

Google Sheets Node > Append Operation

Configure Google Sheets Output

Create a new sheet or update an existing one with the reconciliation results. This writes the missing contacts back to Google Sheets for review.

1. 1Add another Google Sheets node on one output path
2. 2Select 'Append' operation
3. 3Choose your results spreadsheet (can be same or different sheet)
4. 4Map the contact fields to appropriate columns

Start Node > Trigger Configuration

Set Manual Trigger

Configure when this reconciliation runs. Manual trigger lets you run it on-demand, or you can schedule it to run automatically.

1. 1Click the 'Manual Trigger' node at the start
2. 2Change to 'Schedule Trigger' if you want automation
3. 3Set frequency to weekly or monthly for contact reconciliation
4. 4Configure the specific day and time to run

Workflow > Execute Workflow

Test Full Workflow

Execute the complete workflow to verify it properly compares contact lists and identifies missing records. Check both output paths for accuracy.

1. 1Click 'Execute Workflow' button in the top toolbar
2. 2Monitor each node's execution status and output
3. 3Verify the comparison logic found actual missing contacts
4. 4Check that results were written to Google Sheets correctly