ThumbAPI + n8n: The Ultimate Thumbnail Automation Guide

Use the Official ThumbAPI Community Node

Install the dedicated n8n-nodes-thumbapi package and use ThumbAPI as a native n8n node — one drop-in, no Code node, no manual base64 decoding. The node returns the generated image as n8n binary data, ready to flow into Google Drive, S3, WordPress, Slack, or any downstream node that accepts files.

Install (60 seconds)

1. In n8n, open Settings → Community Nodes
2. Click Install
3. Enter n8n-nodes-thumbapi
4. Accept the risk notice → Install

The ThumbAPI node appears in your nodes panel and is searchable as "ThumbAPI".

Verify the connection (no signup, no credits)

Drop the ThumbAPI node onto your canvas. At the top of the parameters panel, enable Use Public Test Key. The default title is already filled in — just pick a format and click Execute step. You'll get a placeholder thumbnail back in seconds, no credential required.

Switch to your real API key

Disable Use Public Test Key, then create a new ThumbAPI credential with your real key from the ThumbAPI dashboard → API Setup. That's it — every generated thumbnail flows out as binary data on the node's output.

Node parameters

• Title, Format, Category, Model, Output Format — the basics
• Use Saved Photo / Use Saved Logo — toggle on to include your saved Personal Photo or brand Logo (upload once in the dashboard)
• Custom Assets ID — point to a saved reference dataset for brand-consistent styling
• Additional Options → Inline Photo / Logo — pass a per-request base64 image to override saved assets
• Put Output In Binary — when on (default), the base64 response is auto-decoded into n8n binary data

Pro Developer Tip: Dynamic Asset Overrides

If you are building a tool for third parties, you don't have to rely on dashboard assets. You can pass a photoImage (max 2MB) or logoImage (max 1MB) as a Base64 string directly in your n8n request body. This allows your workflow to generate unique thumbnails for different guests or products on the fly.

{
  "title": "{{ $json.title }}",
  "format": "youtube",
  "usePhoto": true,
  "photoImage": "{{ $json.guestPhotoBase64 }}",
  "outputFormat": "webp"
}

Quick Test (No Account Needed)

Want to test the workflow without creating an account or using your credits? Use our Public Test Key:

• Header Name: x-api-key
• Test Value: thumbapi_test

This key returns a static “Success” placeholder image so you can verify your n8n connection before using real credits. It does not generate real thumbnails — for that you need to sign up at app.thumbapi.dev (free tier: 50 credits/month) and swap thumbapi_test for your real API key.

Copy the test workflow below, paste it into n8n, and create a Header Auth credential with the test key above:

{
  "nodes": [
    {
      "parameters": {
        "values": {
          "string": [
            {
              "name": "title",
              "value": "Testing ThumbAPI Connection"
            }
          ]
        }
      },
      "name": "Set Test Title",
      "type": "n8n-nodes-base.set",
      "typeVersion": 1,
      "position": [450, 300]
    },
    {
      "parameters": {
        "method": "POST",
        "url": "https://api.thumbapi.dev/v1/generate",
        "sendHeaders": true,
        "headerParameters": {
          "parameters": [
            {
              "name": "x-api-key",
              "value": "thumbapi_test"
            }
          ]
        },
        "sendBody": true,
        "specifyBody": "json",
        "jsonBody": "={\n  \"title\": \"{{ $json.title }}\",\n  \"format\": \"youtube\",\n  \"outputFormat\": \"webp\"\n}"
      },
      "name": "ThumbAPI Request",
      "type": "n8n-nodes-base.httpRequest",
      "typeVersion": 3,
      "position": [670, 300]
    },
    {
      "parameters": {
        "jsCode": "const base64String = $input.item.json.image;\nconst base64Data = base64String.includes(',') ? base64String.split(',')[1] : base64String;\n\nreturn {\n  json: {\n    format: $input.item.json.format,\n    outputFormat: $input.item.json.outputFormat\n  },\n  binary: {\n    data: {\n      data: base64Data,\n      fileName: `thumbnail.${$input.item.json.outputFormat || 'webp'}`,\n      mimeType: `image/${$input.item.json.outputFormat || 'webp'}`\n    }\n  }\n};"
      },
      "name": "Process Image",
      "type": "n8n-nodes-base.code",
      "typeVersion": 1,
      "position": [890, 300]
    }
  ],
  "connections": {
    "Set Test Title": {
      "main": [
        [
          {
            "node": "ThumbAPI Request",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "ThumbAPI Request": {
      "main": [
        [
          {
            "node": "Process Image",
            "type": "main",
            "index": 0
          }
        ]
      ]
    }
  }
}