MongoDB Realm Has Arrived

MongoDB Realm helps you build modern mobile apps, faster. Use the Realm Mobile Database alongside Realm Sync (beta) to keep app data up-to-date in real time across multiple users, devices, and the MongoDB backend. Stop worrying about network availability and focus on building offline-first apps, with the innovative features your users will love.

BUILD BETTER APPS FASTER™. The new standard in data synchronization

Realm helps companies build engaging mobile applications with minimal development time. Learn why every day hundreds of thousands of developers choose Realm.

Start a Free Trial Now

Build with world-class features

The Realm Platform enables any development team, no matter the size, to include difficult-to-build features like two‑way data sync and realtime collaboration. Devote more time to what makes your app truly unique and less time to maintaining services.

Learn More Contact Sales

Realm Database

Use the Realm Database to save data in minutes so you can build mobile apps in a fraction of the time. Our object database is a simple alternative to SQLite and Core Data and proudly open source. Available for Java, Swift, Objective‑C, JavaScript, and Xamarin.

Learn More
class Dog {}

Dog.schema = {
  name: 'Dog',
  properties: {
    name: 'string',
    age: 'int',

let realm = new Realm();
realm.write(() => {
  realm.create('Dog', {name: 'Rex', age: 1});

let pups = realm.objects('Dog').filtered('age < 2');
@interface Dog : RLMObject
@property NSString *name;
@property NSInteger age;
@implementation Dog

Dog *dog = [Dog new]; = @"Rex";
dog.age = 1;

RLMRealm *realm = [RLMRealm defaultRealm];
[realm transactionWithBlock:^{
  [realm addObject:dog];

RLMResults<Dog *> *allDogs = [Dog allObjects];
RLMResults<Dog *> *pups = [allDogs objectsWhere:@"age < 2"];
class Dog: Object {
  @objc dynamic var name = ""
  @objc dynamic var age = 0

let dog = Dog() = "Rex"
dog.age = 1

let realm = try! Realm()
try! realm.write {

let pups = realm.objects(Dog.self).filter("age < 2")
public class Dog extends RealmObject {
  public String name;
  public int age;

Dog dog = new Dog(); = "Rex";
dog.age = 1;

Realm realm = Realm.getDefaultInstance();

RealmResults<Dog> pups = realm.where(Dog.class)
                               .lessThan("age", 2)
public class Dog : RealmObject 
  public string Name { get; set; }
  public int Age { get; set; }

var realm = Realm.GetInstance();
realm.Write(() => 
  realm.Add(new Dog
    Name = "Rex",
    Age = 1

var pups = realm.All<Dog>().Where(d => d.Age < 2);

Realm Platform

Deploy data sync for your mobile apps use Realm Database and create reactive app experiences in as little as 10 lines of code. Realm Object Server and Realm Database combine to make the Realm Platform.

Try Realm Cloud
Learn More
// Authenticating the User
[RLMSyncUser logInWithCredentials:[RLMSyncCredentials credentialsWithGoogleToken:@"google token"]
                    authServerURL:[NSURL URLWithString:@""]
                     onCompletion:^(RLMSyncUser *user, NSError *error) {
  if (user) {
    // Opening a remote Realm
    NSURL *realmURL = [NSURL URLWithString:@"realm://"];
    RLMRealmConfiguration *config = [[RLMRealmConfiguration alloc] init];
    config.syncConfiguration = [user configurationWithURL: realmURL];
    RLMRealm *realm = [RLMRealm realmWithConfiguration:config error:nil];
    // Any changes made to this Realm will be synced across all devices!
  } else if (error) {
    // handle error
// Authenticating the User
SyncUser.logIn(with: .google(token: "google token"),
               server: URL(string: "")!)
{ user, error in
  if let user = user {
    // Opening a remote Realm
    let realm = try! Realm(configuration: user.configuration())
    // Any changes made to this Realm will be synced across all devices!
  } else if let error = error {
    // handle error
// Authenticating the User
User user = User.login("google token"),
// Opening a remote Realm
String realmURL = "realm://";
Realm realm = Realm.getInstance(user.getDefaultConfiguration());
// Any changes made to this Realm will be synced across all devices!
// Authenticating the User
Realm.Sync.User.registerWithProvider('', 'google', googleAccessToken, (error, user) => {
  if (!error) {
    // Opening a remote Realm
    var realm = new Realm({
      sync: {
        user: user,
        url: 'realm://',
    // Any changes made to this Realm will be synced across all devices!
var user = await User.LoginAsync(Credentials.Google("google token"),
                                 new Uri(""));

var realmUrl = new Uri("realm://");
var realm = Realm.GetInstance(user.configuration());
// Any changes made to this Realm will be synced across all devices!

Read a Whitepaper

Learn about Realm's best practices, approach to identity, access control, auditing and logging and encryption. Check out some of our whitepapers below.

Read more

Try a Demo

Learn how to get a synchronized Realm up and running with just 20 lines of code, and discover the power of server-side event handling in a simple demo.

Try a Demo

Watch a Webinar

Get a clear and practical overview of the Realm Platform and its top use cases in these presentations and demos.

Watch now

Get Started with Realm


Cartasite delivers industrial IoT

Using Realm Platform, Cartasite built an offline-first app for heavy industries that seamlessly syncs field data with backend systems. Read more

View more customer stories >

Integral Studio brings creative ideas to life

Digital management company uses Realm Platform to build innovative, reactive apps that bring musicians and their fans closer together. Read more

View more customer stories >

Thread Learning brings education into the digital age

Realm Platform helps special education teams coordinate care by syncing data in real-time across multiple devices. Read more

View more customer stories >

Arccos Golf ups its game with Realm

Arccos delivers a fast, responsive app experience with both online and offline availability for golfers around the world. Read more

View more customer stories >

Realtime collaboration in as little as 10 lines of code

See the Realm developer demo application in action

Watch the video

Logos of companies using Realm, including Amazon, Google, Hipmunk, Starbucks, and more

Over 2 billion users rely on Realm

Trusted by Fortune 500 mainstays, innovative startups, and #1‑ranked app store successes, Realm is built into apps used by hundreds of millions of people every day.

Read more from our Customers

See why over 100,000 developers choose Realm

Start using Realm Platform Try the Database