A digital content system enables users of the content system to access, view and interact with digital content items in a safe, efficient and enjoyable online environment. The content system pre-filters an image content item and determines whether the content item is suspicious of having unsafe content, e.g., nudity and pornography. For example, the content system pre-filters an image content item based on the source of the image content item. A content item from a source known for providing safe content is determined to be safe. The content system determines an image content item to be safe if the content item matches a content item known to be safe or if the content item contains less than a threshold amount of human skin. The content system may further verify the content of the image content item with a verification service and takes remedial actions based on the verification result.