Automatically Add Watermarks to PDFs in Google Drive Using n8n and PDF.co

Step 1: Prepare the Google Drive Folders

Create two folders:

• INPUT_FOLDER for PDFs awaiting processing
• OUTPUT_FOLDER for completed PDFs

Keeping them separate prevents processed files from triggering the workflow again.

Step 2: Add the Google Drive Trigger

Add Google Drive Trigger and configure it to watch INPUT_FOLDER for newly created files.

Connect your Google Drive account and test the trigger with a sample PDF. The result should include the file ID and filename.

Step 3: Download the PDF

Add a Google Drive node after the trigger.

Configure it to download the file:

• Operation: Download
• File ID: Map the ID from the trigger
• Binary Output Field: data

This provides the actual PDF file rather than a Drive preview link.

Step 4: Upload the File to PDF.co

Add PDF.co API and select Upload File.

Configure the node:

• Binary File: True
• Input Binary Field: data
• File Name: Map the original Google Drive filename

The node uploads the PDF securely and returns a temporary PDF.co URL.

Step 5: Add the Watermark

Add another PDF.co API node and select Add Text/Images to PDF.

Map the URL returned by the upload node into the source URL field.

Add this text annotation:

{
  "text": "CONFIDENTIAL",
  "x": 105,
  "y": 412,
  "size": 100,
  "color": "#662563EB",
  "fontBold": true,
  "fontName": "Arial",
  "alignment": "center",
  "pages": "0-"
}

The color uses AARRGGBB format. 66 adds transparency, while 2563EB defines the blue color.

Use 0- to apply the watermark to every page. Adjust the coordinates and font size for your document layout. PDF.co’s PDF Edit Add Helper can be used to determine suitable coordinates.

Set the output filename to the original filename or another descriptive value.

Step 6: Download the Watermarked PDF

Add an HTTP Request node:

• Method: GET
• URL: Map the URL returned by the watermark node
• Response Format: File
• Binary Output Field: data

This downloads the processed PDF into n8n as binary data.

Step 7: Save the PDF to Google Drive

Add Google Drive and select Upload.

Configure the node:

• Input Binary Field: data
• File Name: Watermarked_ followed by the original filename
• Folder: Select OUTPUT_FOLDER
• Drive: Select the appropriate Google Drive

Step 8: Test and Activate the Workflow

Run the workflow and upload a sample PDF to INPUT_FOLDER.

Confirm that PDF.co adds the watermark and that the processed file appears in OUTPUT_FOLDER. Once the test succeeds, activate the workflow.