1. Contentful: Contentful is a headless content management system (CMS) that allows users to manage and deliver content to multiple platforms through a single API. One key difference is its flexible content modeling, where users can define and create custom content types and fields to match their specific needs. This allows for a highly customizable content structure and enables seamless integration with existing systems.

2. Sanity: Sanity is another headless CMS that emphasizes real-time collaboration and a structured content approach. One key difference is its use of a flexible schema-less data model, where users can easily modify and extend content models without the need for migrations or predefined schemas. This provides a lot of flexibility and agility in content creation and management, making it ideal for projects with changing requirements.

3. prismic.io: prismic.io is a headless CMS that focuses on enabling dynamic and interactive content creation. One key difference is its rich content fields, which include options for rich text editing, images, videos, and more. These fields allow for the creation of visually appealing and engaging content without requiring extensive frontend development. Additionally, prismic.io offers a rich set of APIs and tools for managing content and delivering it to various platforms.

4. Contentful: Contentful offers advanced localization features, allowing users to easily create and manage multi-language content. It provides support for various translation workflows, including manual translation, machine translation, and synchronization with external translation services. This makes it a great choice for international projects or those targeting a global audience.

5. Sanity: Sanity provides real-time collaboration capabilities, allowing multiple users to work on content simultaneously. It offers a collaborative editing interface where changes made by different users are immediately reflected for others, creating a smooth and efficient content creation process. This feature is particularly beneficial for teams that need to work together on content creation and editing.

6. prismic.io: prismic.io offers a powerful content query API that allows users to easily retrieve and manipulate content. The API provides various filtering, sorting, and pagination options, enabling efficient content retrieval based on specific criteria. This is advantageous for projects with complex content querying requirements or those that need to create dynamic and personalized experiences for their users.

In Summary, Contentful provides a highly customizable content modeling approach, Sanity emphasizes real-time collaboration and structured content, and prismic.io focuses on interactive content creation and dynamic querying capabilities.