How to Generate UUID in Dart/Flutter

Installation

Add the uuid package to your pubspec.yaml:

pubspec.yaml

dependencies:
  uuid: ^4.3.3

# Or run in terminal:
# dart pub add uuid
# flutter pub add uuid

Note: Run flutter pub get or dart pub get after adding the dependency.

Generate UUID v4 (Random)

The most common use case - generating random UUIDs:

Dart

import 'package:uuid/uuid.dart';

void main() {
  var uuid = Uuid();

  // UUID v4 (random) - most common
  String v4 = uuid.v4();
  print(v4);  // 550e8400-e29b-41d4-a716-446655440000
  
  // Generate multiple
  for (int i = 0; i < 5; i++) {
    print(uuid.v4());
  }
  
  // Use with options
  var options = {
    'random': Uuid.NAMESPACE_NIL  // Custom random source
  };
  String customV4 = uuid.v4(options: options);
}

All UUID Versions

Generate different UUID versions for various use cases:

Dart

import 'package:uuid/uuid.dart';

void main() {
  var uuid = Uuid();

  // UUID v1 (timestamp + MAC address)
  String v1 = uuid.v1();
  print('v1: $v1');
  
  // UUID v4 (random) - most common
  String v4 = uuid.v4();
  print('v4: $v4');
  
  // UUID v5 (SHA-1 hash based)
  String v5 = uuid.v5(Uuid.NAMESPACE_URL, 'https://example.com');
  print('v5: $v5');
  
  // UUID v6 (timestamp, ordered)
  String v6 = uuid.v6();
  print('v6: $v6');
  
  // UUID v7 (Unix timestamp, sortable)
  String v7 = uuid.v7();
  print('v7: $v7');
  
  // UUID v8 (custom format)
  String v8 = uuid.v8();
  print('v8: $v8');
}

Validation

Validate UUID format and check versions:

Dart

import 'package:uuid/uuid.dart';

bool isValidUuid(String str) {
  return Uuid.isValidUUID(fromString: str);
}

void main() {
  // Validate UUID
  print(isValidUuid('550e8400-e29b-41d4-a716-446655440000'));  // true
  print(isValidUuid('not-a-uuid'));  // false
  
  // Check with validation levels
  print(Uuid.isValidUUID(
    fromString: '550e8400-e29b-41d4-a716-446655440000',
    validationMode: ValidationMode.strictRFC4122
  ));
  
  // Parse and validate
  String input = '550e8400-e29b-41d4-a716-446655440000';
  if (Uuid.isValidUUID(fromString: input)) {
    print('Valid UUID: $input');
  } else {
    print('Invalid UUID format');
  }
}

Flutter Model with UUID

Use UUIDs as primary keys in Flutter models:

Dart - Flutter Model

import 'package:uuid/uuid.dart';

class TodoItem {
  final String id;
  final String title;
  final String description;
  bool isComplete;
  final DateTime createdAt;

  TodoItem({
    String? id,
    required this.title,
    this.description = '',
    this.isComplete = false,
    DateTime? createdAt,
  })  : id = id ?? const Uuid().v4(),
        createdAt = createdAt ?? DateTime.now();

  // To JSON
  Map toJson() => {
        'id': id,
        'title': title,
        'description': description,
        'isComplete': isComplete,
        'createdAt': createdAt.toIso8601String(),
      };

  // From JSON
  factory TodoItem.fromJson(Map json) => TodoItem(
        id: json['id'],
        title: json['title'],
        description: json['description'] ?? '',
        isComplete: json['isComplete'] ?? false,
        createdAt: DateTime.parse(json['createdAt']),
      );

  // Copy with
  TodoItem copyWith({
    String? id,
    String? title,
    String? description,
    bool? isComplete,
    DateTime? createdAt,
  }) =>
      TodoItem(
        id: id ?? this.id,
        title: title ?? this.title,
        description: description ?? this.description,
        isComplete: isComplete ?? this.isComplete,
        createdAt: createdAt ?? this.createdAt,
      );
}

// Usage
void main() {
  var todo = TodoItem(title: 'Learn Dart UUID');
  print('Todo ID: ${todo.id}');
}

Flutter State Management with UUID

Integrate UUIDs with Provider state management:

Flutter - Provider

import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:uuid/uuid.dart';

class TodoProvider extends ChangeNotifier {
  final List _todos = [];
  final uuid = Uuid();

  List get todos => _todos;

  void addTodo(String title) {
    final todo = TodoItem(
      id: uuid.v4(),
      title: title,
    );
    _todos.add(todo);
    notifyListeners();
  }

  void toggleTodo(String id) {
    final index = _todos.indexWhere((t) => t.id == id);
    if (index != -1) {
      _todos[index] = _todos[index].copyWith(
        isComplete: !_todos[index].isComplete,
      );
      notifyListeners();
    }
  }

  void deleteTodo(String id) {
    _todos.removeWhere((t) => t.id == id);
    notifyListeners();
  }
}

// Flutter Widget
class TodoListView extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Consumer(
      builder: (context, provider, child) {
        return ListView.builder(
          itemCount: provider.todos.length,
          itemBuilder: (context, index) {
            final todo = provider.todos[index];
            return ListTile(
              key: Key(todo.id),  // Use UUID as key
              title: Text(todo.title),
              trailing: Checkbox(
                value: todo.isComplete,
                onChanged: (_) => provider.toggleTodo(todo.id),
              ),
            );
          },
        );
      },
    );
  }
}

SQLite Database Integration

Use UUIDs with sqflite for local storage:

Flutter - sqflite

import 'package:sqflite/sqflite.dart';
import 'package:path/path.dart';
import 'package:uuid/uuid.dart';

class DatabaseHelper {
  static final DatabaseHelper instance = DatabaseHelper._init();
  static Database? _database;
  final uuid = Uuid();

  DatabaseHelper._init();

  Future get database async {
    if (_database != null) return _database!;
    _database = await _initDB('todos.db');
    return _database!;
  }

  Future _initDB(String filePath) async {
    final dbPath = await getDatabasesPath();
    final path = join(dbPath, filePath);

    return await openDatabase(
      path,
      version: 1,
      onCreate: _createDB,
    );
  }

  Future _createDB(Database db, int version) async {
    await db.execute('''
      CREATE TABLE todos (
        id TEXT PRIMARY KEY,
        title TEXT NOT NULL,
        description TEXT,
        is_complete INTEGER NOT NULL,
        created_at TEXT NOT NULL
      )
    ''');
  }

  Future create(TodoItem todo) async {
    final db = await instance.database;
    
    final id = uuid.v4();
    final todoWithId = todo.copyWith(id: id);
    
    await db.insert('todos', todoWithId.toJson());
    return todoWithId;
  }

  Future readTodo(String id) async {
    final db = await instance.database;
    
    final maps = await db.query(
      'todos',
      where: 'id = ?',
      whereArgs: [id],
    );

    if (maps.isNotEmpty) {
      return TodoItem.fromJson(maps.first);
    }
    return null;
  }

  Future> readAllTodos() async {
    final db = await instance.database;
    final result = await db.query('todos');
    return result.map((json) => TodoItem.fromJson(json)).toList();
  }

  Future delete(String id) async {
    final db = await instance.database;
    return await db.delete(
      'todos',
      where: 'id = ?',
      whereArgs: [id],
    );
  }
}

Firebase Integration

Use UUIDs with Cloud Firestore:

Flutter - Firestore

import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:uuid/uuid.dart';

class FirestoreTodoService {
  final FirebaseFirestore _firestore = FirebaseFirestore.instance;
  final uuid = Uuid();

  Future createTodo(String title) async {
    final id = uuid.v4();
    final todo = TodoItem(
      id: id,
      title: title,
    );

    await _firestore
        .collection('todos')
        .doc(id)
        .set(todo.toJson());

    return todo;
  }

  Future getTodo(String id) async {
    final doc = await _firestore
        .collection('todos')
        .doc(id)
        .get();

    if (doc.exists) {
      return TodoItem.fromJson(doc.data()!);
    }
    return null;
  }

  Stream> getTodosStream() {
    return _firestore
        .collection('todos')
        .orderBy('createdAt', descending: true)
        .snapshots()
        .map((snapshot) => snapshot.docs
            .map((doc) => TodoItem.fromJson(doc.data()))
            .toList());
  }

  Future updateTodo(String id, Map updates) async {
    await _firestore
        .collection('todos')
        .doc(id)
        .update(updates);
  }

  Future deleteTodo(String id) async {
    await _firestore
        .collection('todos')
        .doc(id)
        .delete();
  }
}

Riverpod State Management

Modern state management with Riverpod:

Flutter - Riverpod

import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:uuid/uuid.dart';

final uuidProvider = Provider((ref) => Uuid());

class TodoNotifier extends StateNotifier> {
  TodoNotifier(this.uuid) : super([]);
  
  final Uuid uuid;

  void addTodo(String title) {
    final todo = TodoItem(
      id: uuid.v4(),
      title: title,
    );
    state = [...state, todo];
  }

  void toggleTodo(String id) {
    state = [
      for (final todo in state)
        if (todo.id == id)
          todo.copyWith(isComplete: !todo.isComplete)
        else
          todo,
    ];
  }

  void removeTodo(String id) {
    state = state.where((todo) => todo.id != id).toList();
  }
}

final todoProvider = StateNotifierProvider>((ref) {
  final uuid = ref.watch(uuidProvider);
  return TodoNotifier(uuid);
});

// Usage in Widget
class TodoScreen extends ConsumerWidget {
  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final todos = ref.watch(todoProvider);
    
    return ListView.builder(
      itemCount: todos.length,
      itemBuilder: (context, index) {
        final todo = todos[index];
        return ListTile(
          key: ValueKey(todo.id),
          title: Text(todo.title),
          trailing: IconButton(
            icon: Icon(Icons.delete),
            onPressed: () {
              ref.read(todoProvider.notifier).removeTodo(todo.id);
            },
          ),
        );
      },
    );
  }
}

Other Programming Language UUID Guides

Python UUID JavaScript UUID Java UUID C# UUID PHP UUID Go UUID Node.js UUID TypeScript UUID Rust UUID Ruby UUID Swift UUID Kotlin UUID Bash UUID PowerShell UUID C/C++ UUID Scala UUID R UUID

Generate UUID in Dart

Installation

Generate UUID v4 (Random)

All UUID Versions

Validation

Flutter Model with UUID

Flutter State Management with UUID

SQLite Database Integration

Firebase Integration

Riverpod State Management

Other Programming Language UUID Guides

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