What are some alternatives?
When comparing Zenfolio and 500px, you can also consider the following products
Flickr - image and video hosting website
Pixpa - Pixpa is an all-in-one platform to create beautiful, professional portfolio websites, client galleries and online stores without any coding knowledge.
Imgur - Imgur is a free and simple image hosting service with image editing feature. Signup is optional.
SmugMug - SmugMug is a platform that allows amateurs and professional photographers to host their pictures and create a virtual gallery for promoting and selling their work.
Google Photos - All your photos are backed up safely, organized and labeled automatically, so you can find them fast, and share them how you like.
Format - Online portfolio platform for creatives; photographers, designers, artists and more.