Adding your images will help bring your Tumblr content to life and engage your audience. When you’re ready to share, select saved RGB images for a successful upload. Tumblr includes an automatic scale-down feature that will resize images to fit the format, such as a wide or horizontal header photo, within the layout design. Before you post, make sure your images do not violate copyright laws.

Maximum Sizes

Select an image file in one of the accepted formats, such as BMP, JPG/JPEG, GIF or PNG. The file must be smaller than 10MB. Tumblr allows animated GIF files up to 1MB and up to 500 pixels wide. A specific blog theme will have its own upload limits, such as 500 pixels wide by 750 pixels tall.

Adjust Portrait Photos

Update your avatar with a square photo 128 by 128 pixels or larger to fit the avatar format on the Dashboard. Edit a rectangular image with a photo editing program, such as Windows Photo Gallery, to crop your original image. For example, Photo Gallery's Edit tab on the ribbon includes the Crop button in the Adjustments group. Click "Crop," point over "Proportion" and then select "Square." Click "Apply Crop" on the Crop's menu to save this square format to upload as your avatar.