YouTube Thumbnail Generator with OpenAI & Apify

This n8n workflow automatically generates a custom YouTube thumbnail using OpenAI’s DALL·E based on a YouTube video’s transcript and title. It uses Apify actors to extract video metadata and transcript, then processes the data into a prompt for DALL·E and creates a high-resolution image for use as a thumbnail.

✅ Key Features

• 📥 Form Trigger: Accepts a YouTube URL from the user.
• 🧠 GPT-4o Prompt Creation: Summarizes transcript and title into a descriptive DALL·E prompt.
• 🎨 DALL·E Image Generation: Produces a clean, minimalist YouTube thumbnail with OpenAI’s image model.
• 🪄 Automatic Image Resizing: Resizes final image to YouTube specs (1280x720).
• 🔍 Apify Integration: Uses two Apify actors:
  • Youtube-Transcript-Scraper to extract transcript
  • youtube-scraper to get video metadata like title, channel, etc.

🧰 What You'll Need

• OpenAI API Key
• Apify Account & API Token
• YouTube video URL
• n8n instance (cloud or self-hosted)

🔧 Step-by-Step Setup

1️⃣ Form & Parameter Assignment

• Node: Form Trigger
• How it works: Collects the YouTube URL via a form embedded in your n8n instance.
• API Required: None
• Additional Node: Set
  • Converts the single input URL into the format Apify expects: an array of { url } objects.

2️⃣ Apify Actors for Data Extraction

• Node: HTTP Request (Query Metadata)
  • URL: https://api.apify.com/v2/acts/streamers~youtube-scraper/run-sync-get-dataset-items
  • Payload: JSON with startUrls array and filtering options like maxResults, isHD, etc.
• Node: HTTP Request (Query Transcript)
  • URL: https://api.apify.com/v2/acts/topaz_sharingan~Youtube-Transcript-Scraper/run-sync-get-dataset-items
  • Payload: startUrls array
• API Required: Apify API Token (via HTTP Query Auth)
• Notes: You must have an Apify account and actor credits to use these actors.

3️⃣ OpenAI GPT-4o & DALL·E Generation

• Node: OpenAI (Prompt Creator)
  • Uses the transcript and title to generate a DALL·E-compatible visual prompt.
• Node: OpenAI (Image Generator)
  • Resource: image
  • Model: DALL·E (default with GPT-4o key)
• API Required: OpenAI API Key
• Prompt Strategy:

Create a minimalist YouTube thumbnail in an illustration style. The background should be a very simple, uncluttered setting with soft, ambient lighting that subtly reflects the essence of the transcript. The overall mood should be professional and non-cluttered, ensuring that the text overlay stands out without distraction. Do not include any text.

4️⃣ Resize for YouTube Format

• Node: Edit Image
• Purpose: Resize final image to 1280x720 with ignoreAspectRatio set to true.
• No API required — this runs entirely in n8n.

👤 Created By

Robert Breen
Automation Consultant | AI Workflow Designer | n8n Expert
📧 [email protected]
🌐 ynteractive.com
🔗 LinkedIn

🏷️ Tags

openai dalle youtube thumbnail generator apify ai automation image generation illustration prompt engineering gpt-4o