1. Key Difference 1: Themes and Styles CodeMirror allows users to customize the theme and style of the code editor according to their preferences. It provides a wide range of built-in themes and styles, and users can also create their own custom themes. On the other hand, CodeSandbox offers a limited set of pre-defined themes and styles, and users do not have the option to create their own custom themes.

2. Key Difference 2: Collaboration Features CodeMirror does not have built-in collaboration features. It is primarily designed as a code editor for individual use or for embedding in other applications. In contrast, CodeSandbox is specifically designed for collaborative coding. It allows multiple users to work on the same codebase simultaneously, with real-time updates and the ability to see each other's changes.

3. Key Difference 3: Integrated Tools CodeMirror does not come with built-in tools for tasks like code linting, debugging, or running code. It mainly focuses on providing a high-quality code editing experience. CodeSandbox, on the other hand, includes integrated tools for tasks like code linting, running code in various environments and frameworks, and debugging, making it more suitable for development and testing.

4. Key Difference 4: Embeddability CodeMirror is highly flexible and can be easily embedded in web applications or websites. It provides a simple API for integration and customization. CodeSandbox, on the other hand, is primarily a web-based development environment. While it does offer embedding options, its main focus is on providing a complete development environment in the browser.

5. Key Difference 5: Project Management CodeMirror does not have built-in project management features. It is primarily designed for editing individual files or code snippets. CodeSandbox, on the other hand, includes project management features like file organization, version control integration, and the ability to collaborate on entire codebases, making it more suitable for larger-scale development projects.

6. Key Difference 6: Availability CodeMirror is an open-source project and is freely available for use and modification. It can be downloaded and used offline. CodeSandbox, on the other hand, is a cloud-based development environment and requires an internet connection for use. While it offers a free tier, additional features and capabilities are available through paid plans.

In summary, CodeMirror is a customizable code editor primarily focused on individual use or embedding in applications, while CodeSandbox is a collaborative development environment with integrated tools and project management features.