Test-Json

Test-Json
    [-Json] <String>
    [-Options <String[]>]
    [<CommonParameters>]

Test-Json
    [-Json] <String>
    [-Schema] <String>
    [-Options <String[]>]
    [<CommonParameters>]

Test-Json
    [-Json] <String>
    -SchemaFile <String>
    [-Options <String[]>]
    [<CommonParameters>]

Test-Json
    -Path <String>
    [-Options <String[]>]
    [<CommonParameters>]

Test-Json
    [-Schema] <String>
    -Path <String>
    [-Options <String[]>]
    [<CommonParameters>]

Test-Json
    -Path <String>
    -SchemaFile <String>
    [-Options <String[]>]
    [<CommonParameters>]

Test-Json
    -LiteralPath <String>
    [-Options <String[]>]
    [<CommonParameters>]

Test-Json
    [-Schema] <String>
    -LiteralPath <String>
    [-Options <String[]>]
    [<CommonParameters>]

Test-Json
    -LiteralPath <String>
    -SchemaFile <String>
    [-Options <String[]>]
    [<CommonParameters>]

The Test-Json cmdlet tests whether a string is a valid JavaScript Object Notation (JSON) document and can optionally verify that JSON document against a provided schema.

The verified string can then be used with the ConvertFrom-Json cmdlet convert a JSON-formatted string to a JSON object, which is easily managed in PowerShell or sent to another program or web service that access JSON input.

Many web sites use JSON instead of XML to serialize data for communication between servers and web-based apps.

This cmdlet was introduced in PowerShell 6.1

This example tests whether the input string is a valid JSON document.

'{"name": "Ashley", "age": 25}' | Test-Json

True

This example takes a string containing a JSON schema and compares it to an input string.

$schema = @'
{
  "definitions": {},
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "http://example.com/root.json",
  "type": "object",
  "title": "The Root Schema",
  "required": [
    "name",
    "age"
  ],
  "properties": {
    "name": {
      "$id": "#/properties/name",
      "type": "string",
      "title": "The Name Schema",
      "default": "",
      "examples": [
        "Ashley"
      ],
      "pattern": "^(.*)$"
    },
    "age": {
      "$id": "#/properties/age",
      "type": "integer",
      "title": "The Age Schema",
      "default": 0,
      "examples": [
        25
      ]
    }
  }
}
'@
'{"name": "Ashley", "age": "25"}' | Test-Json -Schema $schema -ErrorAction SilentlyContinue

False

In this example, we use the ErrorAction parameter to suppress the error message. Without this parameter the command also outputs an error because the schema expects an integer for age but the JSON input we tested uses a string value instead.

For more information, see JSON Schema.

JSON schema can reference definitions using $ref keyword. The $ref can resolve to a URI that references another file. The SchemaFile parameter accepts literal path to the JSON schema file and allows JSON files to be validated against such schemas.

In this example the schema.json file references definitions.json.

Get-Content schema.json

{
  "description":"A person",
  "type":"object",
  "properties":{
    "name":{
      "$ref":"definitions.json#/definitions/name"
    },
    "hobbies":{
      "$ref":"definitions.json#/definitions/hobbies"
    }
  }
}

Get-Content definitions.json

{
  "definitions":{
    "name":{
      "type":"string"
    },
    "hobbies":{
      "type":"array",
      "items":{
        "type":"string"
      }
    }
  }
}

'{"name": "James", "hobbies": [".NET", "Blogging"]}' | Test-Json -SchemaFile 'schema.json'

True

For more information, see Structuring a complex schema.

This cmdlet supports the common parameters: -Debug, -ErrorAction, -ErrorVariable, -InformationAction, -InformationVariable, -OutBuffer, -OutVariable, -PipelineVariable, -ProgressAction, -Verbose, -WarningAction, and -WarningVariable. For more information, see about_CommonParameters.

You can pipe a JSON string to this cmdlet.

This cmdlet returns $true if the JSON is valid and otherwise $false.

Since PowerShell 6, PowerShell uses the Newtonsoft.Json assemblies for JSON functions. Newtonsoft's implementation includes several extensions to the JSON standard, such as support for comments and use of single quotes. For a full list of features, see the Newtonsoft documentation at https://www.newtonsoft.com/json.

Beginning in PowerShell 7.4, Test-Json uses System.Text.Json for JSON parsing and JsonSchema.NET for schema validation. With these changes, Test-Json:

• No longer supports Draft 4 schemas
• Only supports strictly conformant JSON

For a complete list of differences between Newtonsoft.Json and System.Text.Json, see the Table of differences in Migrate from Newtonsoft.Json to System.Text.Json.

For more information about JSON schema specifications, see the documentation at JSON-Schema.org.