Monitor competitor SEO changes with CustomJS Scraper, Google Sheets & Slack alerts

> ⚠️ Notice:
> Community nodes like @custom-js/n8n-nodes-pdf-toolkit can only be installed on self-hosted instances of n8n.

This n8n workflow demonstrates how to monitor competitor websites for SEO changes by scraping content and updating a Google Sheet. It uses the Scraper node from customjs.space to extract HTML content and parse key SEO elements like title, <h1>, <h2>, and meta description.

What this workflow does

• Reads a list of competitor websites from a Google Sheet.
• Uses the CustomJS Scraper node to fetch raw HTML for each website.
• Extracts important SEO data:
  • Page title
  • <h1> headings
  • <h2> headings
  • Meta description
• Updates the Google Sheet with the latest scraped values and a timestamp.
• Compares the new values with the previous ones:
  • If changes are detected, a Slack notification is sent.

Requirements

• Self-hosted n8n instance.
• CustomJS API key for the Scraper node.
• A Google Sheet containing competitor website URLs.
• Slack workspace (optional, for notifications).

Workflow Steps

1. Schedule Trigger
   Runs automatically (weekly by default, adjustable as needed).

2. Google Sheets – Get Competitor URLs
   Reads competitor website URLs from the configured sheet.

3. CustomJS Scraper – Fetch HTML

   • Inputs each website URL.
   • Returns raw HTML text for analysis.

4. Code – Extract SEO Elements
   Parses the HTML to extract:

   • Title
   • H1s
   • H2s
   • Meta description

5. Google Sheets – Update SEO Data
   Updates the sheet with the new SEO data and a current date.

6. If – Check for SEO Changes
   Compares old vs. new values.

7. Slack Notification – Alert on Changes
   Sends a message to Slack when updates are detected.

Usage

1. Get API key from CustomJS

   • Sign up on the CustomJS platform.
   • Navigate to your profile page.
   • Click “Show” to reveal your API key.

2. Set Credentials for CustomJS API in n8n

   • Copy your API key into a new CustomJS credential.

3. Prepare your Google Sheet

   • Create a sheet with a column named Websites.
   • Enter competitor URLs (must start with https://).

4. Run or schedule the workflow

   • The workflow will scrape competitor sites, update the sheet, and notify you of any SEO changes.

Example Output

Google Sheet after update:

Slack Notification Example

> ⚠️ Competitor SEO Change Detected!

Website: https://example.com

Title

• Old: Example Title
• New: New Example Title

Meta Description

• Old: Example meta description
• New: Updated example meta description

H1s

• Old: Example Heading
• New: Updated Heading

H2s

• Old: Example Subheading
• New: Updated Subheading

Date: 2025-09-07 12:00:00

Customization Tips

• Change scraping frequency in the Schedule Trigger (daily, weekly, etc.).
• Track additional elements by extending the regex in the Code Node.
• Send alerts to other platforms (e.g., Email, Microsoft Teams, Discord) by swapping the Slack node.
• Store results in a database instead of Google Sheets if long-term history is required.