How to send base64-encoded PDF file from Google Drive to HTTP Request node?

[skkustartup]

Describe the problem/error/question

What is the error message (if any)?

Please share your workflow

(Select the nodes on your canvas and use the keyboard shortcuts CMD+C/CTRL+C and CMD+V/CTRL+V to copy and paste the workflow.)

Share the output returned by the last node

Information on your n8n setup

• n8n version: 1.86.1
• Database (default: SQLite): SQLite (default)
• n8n EXECUTIONS_PROCESS setting (default: own, main): own (default)
• Running n8n via (Docker, npm, n8n cloud, desktop app): n8n cloud
• Operating system: Windows 11

Hi, I’m trying to connect to an external API using the HTTP Request node in n8n.

Here’s my current workflow:

• Google Drive Node

  • Operation: Download
  • Resource: File

• HTTP Request Node

  • Method: POST
  • Content-Type: application/json

According to the API documentation, I need to send the PDF file as a base64-encoded string in the data field of the JSON body.

The Google Drive node successfully downloads the PDF file.
However, I’m not sure how to access the base64-encoded binary data of the file.

I read in the documentation that it might be accessible using binary.data.data,
but when I try that, I get an error saying the data doesn’t exist.

What’s the correct way to reference the base64 data from the Google Drive node
in the HTTP Request node?

Example payload I want to build:

{
  "data": ??? ← What expression should go here?
}

[jabbson]

Try this:

{
  "nodes": [
    {
      "parameters": {},
      "type": "n8n-nodes-base.manualTrigger",
      "typeVersion": 1,
      "position": [
        0,
        0
      ],
      "id": "041b48ed-e174-42b8-8ffc-784abc022199",
      "name": "When clicking ‘Execute workflow’"
    },
    {
      "parameters": {
        "operation": "download",
        "fileId": {
          "__rl": true,
          "value": "1mH8DmqcUAo_QABax_sB0_IM2dnUL26Q5",
          "mode": "list",
          "cachedResultName": "0aa3d1c7-2cad-461f-abba-371446687661.pdf",
          "cachedResultUrl": "https://drive.google.com/file/d/1mH8DmqcUAo_QABax_sB0_IM2dnUL26Q5/view?usp=drivesdk"
        },
        "options": {}
      },
      "type": "n8n-nodes-base.googleDrive",
      "typeVersion": 3,
      "position": [
        208,
        0
      ],
      "id": "f85e06c2-a4b4-43ba-a5d1-6e641cfd834a",
      "name": "Download file",
      "credentials": {
        "googleDriveOAuth2Api": {
          "id": "6qPTH5ldV1hRKhEy",
          "name": "Google Drive Main account"
        }
      }
    },
    {
      "parameters": {
        "operation": "binaryToPropery",
        "options": {}
      },
      "type": "n8n-nodes-base.extractFromFile",
      "typeVersion": 1,
      "position": [
        416,
        0
      ],
      "id": "f45a1c3e-1ddd-4b12-8321-873f108bbd14",
      "name": "Extract from File"
    }
  ],
  "connections": {
    "When clicking ‘Execute workflow’": {
      "main": [
        [
          {
            "node": "Download file",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "Download file": {
      "main": [
        [
          {
            "node": "Extract from File",
            "type": "main",
            "index": 0
          }
        ]
      ]
    }
  },
  "pinData": {},
  "meta": {
    "templateCredsSetupCompleted": true,
    "instanceId": "9423335a0111216c302866f5fc1752af6da6042c706e1cc46ecd439bca874130"
  }
}

This is how you can turn pdf binary to a base64 string.

[skkustartup]

Thank you! However, I have an additional question. When I ran an OCR on the extracted data, it seems that only one of the two PDF pages was OCRed. What could be the issue?

[jabbson]

@skkustartup

If you could create an additional topic about this saparaate issue, that would be great; and for this one, if I was able to answer your question, kindly mark the answer as solution. Thank you.