CloudKit vs LiteDB

CloudKit is Apple’s service for storing structured app and user data in iCloud and synchronizing it across devices and the web. Data is organized in containers with public, private, and shared databases, and synchronization is bidirectional across iOS, iPadOS, macOS, tvOS, watchOS, visionOS, and web apps. CloudKit supports Swift, Objective-C, and JavaScript. Apple Developer Program membership includes up to 1PB of free storage for each app. CloudKit Console lets developers manage containers and schemas, inspect test data, and review telemetry, logs, and alerts. Fields in private databases can be configured for encryption in storage and while travelling to the application. Public databases use World, Authenticated, and Creator roles. Separate sandbox and production environments are provided; production schemas can only be changed in a forward-compatible manner. Automation supports integration tests from Xcode or a CI system, and CKTool JS can be embedded in developer tools. CloudKit JS adds CloudKit support to web apps. A free plan is listed at free, while pricing is from $99/yr. Incoming traffic is throttled by limits and controls that may change over time.

LiteDB is a free, open-source, serverless .NET NoSQL document database distributed as a single DLL. It stores data in one file and supports ACID transactions, with WAL mode for recovery from write failures. Queries can use SQL-like commands or LINQ, and query EXPLAIN plans are available. LiteDB maps POCO classes to BsonDocument and offers a fluent API for custom mapping. Its intended uses include mobile apps, desktop and local applications, application file formats, web applications, and per-user data stores. FileStorage can keep files and streams in the database, though each root BSON document has a documented 16 MB limit. LiteDB describes itself as thread-safe, with cross-collection transactions, no reader locks, and per-collection writer locks. Password-protected datafile encryption uses salted AES; the documentation specifies ECB mode and says changing or removing a password requires rebuilding the file. LiteDB is free for everyone, including commercial use, under the MIT License. It is installable through NuGet, and the project links to LiteDB.Studio as an administration tool.