Chrome Extension troubleshooting

If you're not seeing any active tests when in youtube studio an API key wasn't properly created for the extension, here's some steps you can take to try and create one:
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• uninstall extension
• make sure any ad blockers are disabled

• or allow app.thumbnailtest.com and studio.youtube.com
• reinstall extension
• open app.thumbnailtest.com
• wait on thumbnail test for 20 seconds to make sure an API key is generated successfully (there’s no visual indication currently but it’s being worked on)
• then open YT studio making sure you’re signed on the correct channel
• the overlay should slide in if you have active tests then slide out of screen if everything synced correctly
• refresh test page and data should be there

How to get new API Key for Chrome Extension

• Click on the extension in the toolbar or in the extension list and the settings should popup (Picture below)
• Click on "Remove key"
• Open ThumbnailTest by going to https://app.thumbnailtest.com
• Wait for the page to fully load
• Click on the extension again and it should show that it is connected again.
  

Updated on: 07/06/2025