Isar

What Isar is

Isar is a free, open-source NoSQL database for Flutter apps that need local data access, including when a network connection is unavailable. It runs on Android, iOS and the web, with setup that requires no configuration or boilerplate. A database can hold hundreds of thousands of records and supports efficient asynchronous queries. Developers can use composite and multi-entry indexes, query modifiers, JSON support and built-in full-text search. Queries are statically typed and checked at compile time. Isar handles transactions automatically and rolls back changes when an error occurs; it also provides parallel query operations and multi-isolate support. The Apache-licensed software is free forever at 0.00 USD. There are platform-specific limits: on VM platforms, a prefix where-clause can use only the first 1024 bytes of a string, and objects can be at most 16 MB. On the web, synchronous methods, splitWords() and matches() filters, and NaN are unsupported. Isar adds about 1–1.5 MB to an app download, while Isar Web adds only a few KB.