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Fast Cross Platform Database for Flutter Apps. Supports indexes, FTS, queries etc.

Isar Database

QuickstartDocumentationSample AppsSupport &

Isar [ee-zahr]:

  1. River in Bavaria, Germany.
  2. Database that will make your life easier.

Features #

  • 💙 Made for Flutter. Easy to use, no config, no boilerplate
  • 🚀 Highly scalable The sky is the limit (pun intended)
  • 🍭 Feature rich. Composite & multi-entry indexes, query modifiers, JSON support etc.
  • Asynchronous. Parallel query operations & multi-isolate support by default
  • 🦄 Open source. Everything is open source and free forever!

Isar can do much more (and we are just getting started)

  • 🕵️ Full-text search. Make searching fast and fun
  • 📱 Multiplatform. iOS, Android, Desktop and FULL WEB SUPPORT!
  • 🧪 ACID semantics. Rely on consistency
  • 💃 Static typing. Compile-time checked and autocompleted queries
  • Beautiful documentation. Readable, easy to understand and ever improving

Join the Telegram group for discussion and check out the doc.

If you want to say thank you, star us on GitHub and like us on 🙌💙

Quickstart #

Holy smokes you're here! Let's get started...

1. Add to pubspec.yaml #

  isar: 2.5.0
  isar_flutter_libs: 2.5.0 # contains the binaries

  isar_generator: 2.5.0
  build_runner: any

2. Annotate a Collection #

part 'post.g.dart';

class Post {
  int id = Isar.autoIncrement;

  late String title;

  late DateTime date;

3. Open an instance #

final dir = await getApplicationSupportDirectory(); // path_provider package
final isar = await
  schemas: [PostSchema],
  directory: dir.path,
  inspector: true, // if you want to enable the inspector for debug builds

4. Query the database #

final posts = await isar.posts.filter()
  .titleContains('awesome', caseSensitive: false)

Isar Inspector #

The Isar Inspector allows you to inspect the Isar instances & collections of your app in real time. You can execute queries, switch between instances and sort the data.

CRUD operations #

All basic crud operations are available via the IsarCollection.

final newPost = Post()..title = 'Amazing new database';

await isar.writeTxn((isar) { = await isar.posts.put(newPost); // insert & update

final existingPost = await isar.posts.get(!); // get

await isar.writeTxn((isar) {
  await isar.posts.delete(!); // delete

Queries #

Isar has a powerful query language that allows you to make use of your indexes, filter distinct objects, use complex and() and or() groups, query links and sort the results.

final usersWithPrefix = isar.users
  .nameStartsWith('dan') // use index

final usersLivingInMunich = isar.users
  .addressMatches('*Munich*', caseSensitive: false) // address containing 'munich' (case insensitive)
    shouldSort, // only apply if shouldSort == true
    (q) => q.sortedByAge(),

You can easily define relationships between objects. In Isar they are called links and backlinks:

class Teacher {
    int? id;

    late String subject;

    @Backlink(to: 'teacher')
    final students = IsarLinks<Student>();

class Student {
    int? id;

    late String name;

    final teacher = IsarLink<Teacher>();

Watchers #

With Isar, you can watch Collections, Objects, or Queries. A watcher is notified after a transaction commits successfully and the target actually changes. Watchers can be lazy and not reload the data or they can be non-lazy and fetch new results in the background.

Stream<void> collectionStream = isar.posts.watchLazy;

Stream<List<Post>> queryStream =;

queryStream.listen((newResult) {
  // do UI updates

License #

Copyright 2022 Simon Leier

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
See the License for the specific language governing permissions and
limitations under the License.
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Fast Cross Platform Database for Flutter Apps. Supports indexes, FTS, queries etc.

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