Declaring Defaults in Your Schema

Your schemas can define default values for certain paths. If you create a new document without that path set, the default will kick in.

Note: Mongoose only applies a default if the value of the path is strictly undefined.

const schema = new Schema({
  name: String,
  role: { type: String, default: 'guitarist' }

const Person = db.model('Person', schema);

const axl = new Person({ name: 'Axl Rose', role: 'singer' });
assert.equal(axl.role, 'singer');

const slash = new Person({ name: 'Slash' });
assert.equal(slash.role, 'guitarist');

const izzy = new Person({ name: 'Izzy', role: undefined });
assert.equal(izzy.role, 'guitarist');

// Defaults do **not** run on `null`, `''`, or value other than `undefined`.
const foo = new Person({ name: 'Bar', role: null });
assert.strictEqual(foo.role, null);

await Person.create(axl, slash);

const docs = await Person.find({ role: 'guitarist' });

assert.equal(docs.length, 1);
assert.equal(docs[0].name, 'Slash');

Default Functions

You can also set the default schema option to a function. Mongoose will execute that function and use the return value as the default.

const schema = new Schema({
  title: String,
  date: {
    type: Date,
    // `` returns the current unix timestamp as a number

const BlogPost = db.model('BlogPost', schema);

const post = new BlogPost({ title: '5 Best Arnold Schwarzenegger Movies' });

// The post has a default Date set to now
assert.ok( >= - 1000);
assert.ok( <=;

The setDefaultsOnInsert Option

Mongoose also sets defaults on update() and findOneAndUpdate() when the upsert option is set by adding your schema's defaults to a MongoDB $setOnInsert operator. You can disable this behavior by setting the setDefaultsOnInsert option to false.

const schema = new Schema({
  title: String,
  genre: { type: String, default: 'Action' }

const Movie = db.model('Movie', schema);

const query = {};
const update = { title: 'The Terminator' };
const options = {
  // Return the document after updates are applied
  new: true,
  // Create a document if one isn't found.
  upsert: true

let doc = await Movie.findOneAndUpdate(query, update, options).lean();
doc.genre; // 'Action', Mongoose set a default value.

await Movie.deleteMany({});

doc = await Movie.findOneAndUpdate(query, update, { new: true, upsert: true, setDefaultsOnInsert: false }).lean();
doc.genre; // undefined, Mongoose did not set a default value

You can also set setDefaultsOnInsert to false globally:

mongoose.set('setDefaultsOnInsert', false);

Default functions and this

Unless it is running on a query with setDefaultsOnInsert, a default function's this refers to the document.

const schema = new Schema({
  title: String,
  released: Boolean,
  releaseDate: {
    type: Date,
    default: function() {
      if (this.released) {
      return null;

const Movie = db.model('Movie', schema);

const movie1 = new Movie({ title: 'The Terminator', released: true });

// The post has a default Date set to now
assert.ok(movie1.releaseDate.getTime() >= - 1000);
assert.ok(movie1.releaseDate.getTime() <=;

const movie2 = new Movie({ title: 'The Legend of Conan', released: false });

// Since `released` is false, the default function will return null
assert.strictEqual(movie2.releaseDate, null);