Each time you upload a video, YouTube automatically generates a set of three thumbnails for you to choose from. You can stick with YouTube's proposals or upload a custom thumbnail, preferably a beautiful picture or photo you have prepared beforehand. Prerequisites
- The popular image formats (optimized for the web) are supported: JPEG or PNG.- The maximum file size is 2MB.
Upload your thumbnail
Sign-in to your YouTube channel and then open the Creator Studio > Video Manager > Videos:
Select the desired video and then click on the Edit button > Info and Settings tab:
Click on the Custom Thumbnail button displayed, browse for the image you want to use and click on Save changes:
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