You have the option to download the app version of the service on your desktop or smartphone which will allow you to backup photos easily. Plus it also functions as a good photo editor. It is a cloud storage service that offers you with an unlimited storage space for photos and videos at high quality. The most obvious and the default choice for the Picasa users is Google photos. So down goes our list of a few alternatives that would sufficiently quench your Picasa thirst. 2 Top 10 Alternatives to Picasa in 2019 10 best Picasa alternatives.1.7 Microsoft Photos – Picasa Alternative for Windows 10.