Stackr is described as 'web service for sharing your photo on the internet without any complex methods' and is an website in the Photos & Graphics category. There are more than 25 alternatives to Stackr, not only websites but also apps for a variety of platforms, including Windows, iPhone, Mac and Linux. The best alternative is Imgur, which is free. Other great sites and apps similar to Stackr are Flickr (Freemium), MediaGoblin (Free, Open Source), 500px (Freemium) and PostImage.org (Freemium).
MediaGoblin is a free software media publishing platform that anyone can run. You can think of it as a decentralized alternative to Flickr, YouTube, SoundCloud, etc. It's also: The perfect tool to show and share your media!
500px lets you create stunning professional photo portfolios, find friends, express yourself and connect with likeminded people. It was co-founded by Oleg Gutsol and Evgeny Tchebotarev on Halloween 2009 and 15 million users as of September 2018.
A place for your photos. For you. Your photos were never meant to sit idle on a feed or collect digital dust on a hard drive. SmugMug is home to photographers who believe photos can change the world, even if that world is just your own.