# MongoDB Extended JSON (v2) On this page * [Parsers and Supported Format](https://docs.mongodb.com/manual/reference/mongodb-extended-json/#parsers-and-supported-format) * [BSON Data Types and Associated Representations](https://docs.mongodb.com/manual/reference/mongodb-extended-json/#bson-data-types-and-associated-representations) [JSON](https://docs.mongodb.com/manual/reference/glossary/#term-json)can only represent a subset of the types supported by[BSON](https://docs.mongodb.com/manual/reference/glossary/#term-bson). To preserve type information, MongoDB adds the following extensions to the JSON format: * *Strict mode* . Strict mode representations of BSON types conform to the [JSON RFC](http://www.json.org/) . Any JSON parser can parse these strict mode representations as key/value pairs; however, only the MongoDB internal JSON parser recognizes the type information conveyed by the format. * `mongo` *Shell mode* . The MongoDB internal JSON parser and the [`mongo`](https://docs.mongodb.com/manual/reference/program/mongo/#bin.mongo) shell can parse this mode. The representation used for the various data types depends on the context in which the JSON is parsed. ## Parsers and Supported Format ### Input in Strict Mode The following can parse representations in strict mode\_with\_recognition of the type information. * [REST Interfaces](https://docs.mongodb.com/ecosystem/tools/http-interfaces) * [`mongoimport`](https://docs.mongodb.com/manual/reference/program/mongoimport/#bin.mongoimport) * `--query` option of various MongoDB tools * [MongoDB Compass](https://www.mongodb.com/products/compass) Other JSON parsers, including[`mongo`](https://docs.mongodb.com/manual/reference/program/mongo/#bin.mongo)shell and[`db.eval()`](https://docs.mongodb.com/manual/reference/method/db.eval/#db.eval), can parse strict mode representations as key/value pairs, but\_without\_recognition of the type information. ### Input in`mongo`Shell Mode The following can parse representations in`mongo`shell mode\_with\_recognition of the type information. * [REST Interfaces](https://docs.mongodb.com/ecosystem/tools/http-interfaces) * [`mongoimport`](https://docs.mongodb.com/manual/reference/program/mongoimport/#bin.mongoimport) * `--query` option of various MongoDB tools * [`mongo`](https://docs.mongodb.com/manual/reference/program/mongo/#bin.mongo) shell ### Output in Strict mode [`mongoexport`](https://docs.mongodb.com/manual/reference/program/mongoexport/#bin.mongoexport)and[REST and HTTP Interfaces](https://docs.mongodb.com/ecosystem/tools/http-interfaces)output data in\_Strict mode\_. ### Output in`mongo`Shell Mode [`bsondump`](https://docs.mongodb.com/manual/reference/program/bsondump/#bin.bsondump)outputs in`mongo`*Shell mode*. ## BSON Data Types and Associated Representations The following presents the BSON data types and the associated representations in\_Strict mode\_and`mongo`\_Shell mode\_. ### Binary `data_binary` | | | | | -------------------------------------------- | ----------------------------------------------------------------------------- | ---------------------------- | | Strict Mode | [`mongo`](https://docs.mongodb.com/manual/reference/program/mongo/#bin.mongo) | Shell Mode | | { "$binary": "\", "$type": "\" } | | BinData ( \, \ ) | * ``is the base64 representation of a binary string. * ``is a representation of a single byte indicating the data type. In *Strict mode* it is a hexadecimal string, and in *Shell mode* it is an integer. See the extended bson documentation. ### Date `data_date` | | | | | ---------------------- | ----------------------------------------------------------------------------- | -------------------- | | Strict Mode | [`mongo`](https://docs.mongodb.com/manual/reference/program/mongo/#bin.mongo) | Shell Mode | | { "$date": "\" } | | new Date ( \ ) | In\_Strict mode\_,``is an ISO-8601 date format with a mandatory time zone field following the template`YYYY-MM-DDTHH:mm:ss.mmm<+/-Offset>`. The MongoDB JSON parser currently does not support loading ISO-8601 strings representing dates prior to the[Unix epoch](https://docs.mongodb.com/manual/reference/glossary/#term-unix-epoch). When formatting pre-epoch dates and dates past what your system’s`time_t`type can hold, the following format is used: ``` { "$date" : { "$numberLong" : " < dateAsMilliseconds > " } } ``` In\_Shell mode\_,``is the JSON representation of a 64-bit signed integer giving the number of milliseconds since epoch UTC. ### Timestamp `data_timestamp` | | | | | ------------------------------------------ | ----------------------------------------------------------------------------- | ----------------------- | | Strict Mode | [`mongo`](https://docs.mongodb.com/manual/reference/program/mongo/#bin.mongo) | Shell Mode | | { "$timestamp": { "t": \, "i": \ } } | | Timestamp( \, \ ) | * `<` `t` `>` is the JSON representation of a 32-bit unsigned integer for seconds since epoch. * `<` `i` `>` is a 32-bit unsigned integer for the increment. ### Regular Expression `data_regex` | | | | | ---------------------------------------------------- | ----------------------------------------------------------------------------- | ---------------------- | | Strict Mode | [`mongo`](https://docs.mongodb.com/manual/reference/program/mongo/#bin.mongo) | Shell Mode | | { "$regex": "\", "$options": "\" } | | /\/\ | * `<` `sRegex` `>` is a string of valid JSON characters. * `<` `jRegex` `>` is a string that may contain valid JSON characters and unescaped double quote ( `"` ) characters, but may not contain unescaped forward slash ( `/` ) characters. * `<` `sOptions` `>` is a string containing the regex options represented by the letters of the alphabet. * `<` `jOptions` `>` is a string that may contain only the characters ‘g’, ‘i’, ‘m’ and ‘s’ (added in v1.9). Because the `JavaScript` and `mongo` `Shell` representations support a limited range of options, any nonconforming options will be dropped when converting to this representation. ### OID `data_oid` | | | | | ------------------- | ----------------------------------------------------------------------------- | ------------------- | | Strict Mode | [`mongo`](https://docs.mongodb.com/manual/reference/program/mongo/#bin.mongo) | Shell Mode | | { "$oid": "\" } | | ObjectId( "\" ) | ``is a 24-character hexadecimal string. ### DB Reference `data_ref` | | | | | ------------------------------------- | ----------------------------------------------------------------------------- | ------------------------- | | Strict Mode | [`mongo`](https://docs.mongodb.com/manual/reference/program/mongo/#bin.mongo) | Shell Mode | | { "$ref": "\", "$id": "\" } | | DBRef("\", "\") | * `<` `name` `>` is a string of valid JSON characters. * `<` `id` `>` is any valid extended JSON type. ### Undefined Type `data_undefined` | | | | | ---------------------- | ----------------------------------------------------------------------------- | ---------- | | Strict Mode | [`mongo`](https://docs.mongodb.com/manual/reference/program/mongo/#bin.mongo) | Shell Mode | | { "$undefined": true } | | undefined | The representation for the JavaScript/BSON undefined type. You\_cannot\_use`undefined`in query documents. Consider the following document inserted into the`people`collection: ```javascript db.people.insert( { name : "Sally", age : undefined } ) ``` The following queries return an error: ```javascript db.people.find( { age : undefined } ) db.people.find( { age : { $gte : undefined } } ) ``` However, you can query for undefined values using[`$type`](https://docs.mongodb.com/manual/reference/operator/query/type/#op._S_type), as in: ```javascript db.people.find( { age : { $type : 6 } } ) ``` This query returns all documents for which the`age`field has value`undefined`. ### MinKey `data_minkey` | | | | | ---------------- | ----------------------------------------------------------------------------- | ---------- | | Strict Mode | [`mongo`](https://docs.mongodb.com/manual/reference/program/mongo/#bin.mongo) | Shell Mode | | { "$minKey": 1 } | | MinKey | The representation of the MinKey BSON data type that compares lower than all other types. See[Comparison/Sort Order](https://docs.mongodb.com/manual/reference/bson-type-comparison-order/#faq-dev-compare-order-for-bson-types)for more information on comparison order for BSON types. ### MaxKey `data_maxkey` | | | | | ---------------- | ----------------------------------------------------------------------------- | ---------- | | Strict Mode | [`mongo`](https://docs.mongodb.com/manual/reference/program/mongo/#bin.mongo) | Shell Mode | | { "$maxKey": 1 } | | MaxKey | The representation of the MaxKey BSON data type that compares higher than all other types. See[Comparison/Sort Order](https://docs.mongodb.com/manual/reference/bson-type-comparison-order/#faq-dev-compare-order-for-bson-types)for more information on comparison order for BSON types. ### NumberLong New in version 2.6. `data_numberlong` | | | | | ------------------------------ | ----------------------------------------------------------------------------- | ------------------------- | | Strict Mode | [`mongo`](https://docs.mongodb.com/manual/reference/program/mongo/#bin.mongo) | Shell Mode | | { "$numberLong": "\" } | | NumberLong( "\" ) | `NumberLong`is a 64 bit signed integer. You must include quotation marks or it will be interpreted as a floating point number, resulting in a loss of accuracy. For example, the following commands insert`9223372036854775807`as a`NumberLong`with and without quotation marks around the integer value: ```javascript db.json.insert( { longQuoted : NumberLong("9223372036854775807") } ) db.json.insert( { longUnQuoted : NumberLong(9223372036854775807) } ) ``` When you retrieve the documents, the value of`longUnQuoted`has changed, while`longQuoted`retains its accuracy: ```javascript db.json.find() { "_id" : ObjectId("54ee1f2d33335326d70987df"), "longQuoted" : NumberLong("9223372036854775807") } { "_id" : ObjectId("54ee1f7433335326d70987e0"), "longUnQuoted" : NumberLong("-9223372036854775808") } ``` ### NumberDecimal New in version 3.4. `data_numberdecimal` | | | | | --------------------------------- | ----------------------------------------------------------------------------- | ---------------------------- | | Strict Mode | [`mongo`](https://docs.mongodb.com/manual/reference/program/mongo/#bin.mongo) | Shell Mode | | { "$numberDecimal": "\" } | | NumberDecimal( "\" ) | `NumberDecimal`is a[high-precision decimal](https://github.com/mongodb/specifications/blob/master/source/bson-decimal128/decimal128.rst). You must include quotation marks, or the input number will be treated as a double, resulting in data loss. For example, the following commands insert`123.40`as a`NumberDecimal`with and without quotation marks around the value: ```javascript db.json.insert( { decimalQuoted : NumberDecimal("123.40") } ) db.json.insert( { decimalUnQuoted : NumberDecimal(123.40) } ) ``` When you retrieve the documents, the value of`decimalUnQuoted`has changed, while`decimalQuoted`retains its specified precision: ```javascript db.json.find() { "_id" : ObjectId("596f88b7b613bb04f80a1ea9"), "decimalQuoted" : NumberDecimal("123.40") } { "_id" : ObjectId("596f88c9b613bb04f80a1eaa"), "decimalUnQuoted" : NumberDecimal("123.400000000000") } ```