Dato CMS

The headless Content as a Service (CaaS) platform DatoCMS was built to operate with static websites, mobile apps, and any type of server-side application. It enables team members and non-technical users to manage their content operations.

DatoCMS is a user-friendly, safe, and potent platform that allows marketing, editorial, or development teams to quickly construct sophisticated backends and distribute any type of content.

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.