Storyblok

Storyblok is also a web service, so you only need to register an account to create a project. It is more difficult to use than Contentful, but has more room for customization. In addition to the main entities, here it's possible to make auxiliary ones to use as components of the main entities. Storyblok allows grouping entities and content independently.

Also, this CMS has a unique feature. It can include your code on the frontend to see a preview of the content being created, which is important for content managers.

Of course, Storyblok has some flaws. It's not beginner-friendly, so a bit of learning is required to understand its interface. Then, it is only available in the paid version. Storyblok also has restrictions for entities, content, and files, but they are much wider than in Contentful.

Finally, Storyblok is a good CMS if you have fairly complex data structures in your project and want to fine-tune them.

Contentstack

With the help of a JSON architecture and APIs supported by content delivery networks (CDNs), Contentstack is a headless CMS software that enables businesses to deliver personalized content experiences to audiences via various channels, such as mobile or web devices, augmented or virtual reality platforms, and the Internet of Things (IoT).

Administrators can set up role-based access permissions for adding, amending, publishing, or deleting content entries as well as modify or format photos for a particular device's display.

To offer individualized, multichannel digital experiences, Contentstack brings together business and technology teams from Enterprise, SMB, and Startup organizations