YouTube Thumbnail Downloader Extension

A simple browser extension that lets you download YouTube video thumbnails in one click—directly from YouTube.

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✨ What This Extension Does

• Adds a small download button (⬇️) on every YouTube video thumbnail
• Downloads the best available thumbnail quality automatically
• Works while you scroll, search, or navigate on YouTube
• No redirects, no popups, no data collection

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🚀 Key Features

• ✅ One‑click thumbnail download
• ✅ Highest quality first (up to 1920×1080)
• ✅ Works on all YouTube pages
• ✅ Auto-detects newly loaded videos
• ✅ Clean and non-intrusive UI
• ✅ No special permissions required

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🧩 Supported Browsers

Browser	Support
Chrome	✅ Yes
Edge	✅ Yes
Brave	✅ Yes
Firefox	⚠️ Needs small manifest changes
Safari	❌ Not supported

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📦 Installation Guide (Chrome / Edge)

1. Download or clone this repository

2. Open your browser and go to:

   • Chrome: chrome://extensions/
   • Edge: edge://extensions/

3. Enable Developer mode (top right)

4. Click Load unpacked

5. Select the extension folder

6. Done 🎉 The extension is now active

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🖱️ How to Use

1. Open YouTube
2. Hover over any video thumbnail
3. Click the ⬇️ download button (top-right corner)
4. The thumbnail downloads instantly

📁 File name format:

VIDEO_ID.jpg

Example:

dQw4w9WgXcQ.jpg

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🖼️ Screenshot Guide

📌 Screenshots are placed in the screenshots/ folder

1️⃣ Extension Loaded

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2️⃣ Download Button on Thumbnail

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3️⃣ One‑Click Download

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4️⃣ Downloaded File

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🛠️ How It Works (Simple Explanation)

1. The extension runs on YouTube pages

2. It finds video thumbnails automatically

3. A small ⬇️ button is added to each thumbnail

4. When clicked:

   • Video ID is detected
   • Thumbnail URLs are generated
   • Best available image is downloaded

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📐 Thumbnail Quality Order

The extension tries these in order:

1. maxresdefault (1920×1080)
2. sddefault (640×480)
3. hqdefault (480×360)
4. mqdefault (320×180)
5. default (120×90)

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📁 Project Structure

youtube-thumbnail-downloader/
├── manifest.json
├── script.js
├── icon.png
├── screenshots/
│   ├── 1-extension-loaded.png
│   ├── 2-download-button.png
│   ├── 3-download-action.png
│   └── 4-downloaded-file.png
└── README.md

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❓ Troubleshooting

Button Not Showing?

• Refresh the page
• Scroll down (new videos load dynamically)
• Make sure the extension is enabled

Image Not Downloading?

• Check browser download permissions
• Some videos don’t have max resolution thumbnails

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🔐 Privacy & Safety

• 🔒 No tracking
• 🔒 No analytics
• 🔒 No external servers
• 🔒 Runs only on YouTube

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🧑‍💻 Development

To make changes:

1. Edit script.js
2. Reload the extension in browser

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📜 License

MIT License — free to use, modify, and share.

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🤝 Contributing

Contributions are welcome:

• Bug fixes
• Feature ideas
• UI improvements
• Documentation updates

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❤️ Support

If you like this project:

• ⭐ Star the repository
• 🐛 Report issues
• 💡 Suggest improvements

Happy downloading! 🎉