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YouTube - How to add a branding intro to your videos

Learn how to add a short introduction clip (branding intro) to the videos published on your YouTube channel.
Prerequisites:

Create short branding video (less than 3 seconds) and upload it to your Youtube channel.
Sign-in to your YouTube account.
Click on the small avatar located top-right > Creator Studio.
Go to the Channel section > Branding.
Click on the Add a branding video button.