JSON Schema Validator
Validate JSON data against a JSON Schema. Runs entirely in your browser.
Paste JSON data and a schema
Validation runs automatically as you type
What is JSON Schema?
JSON Schema is a vocabulary that allows you to annotate and validate JSON documents. You define the expected structure — required fields, allowed types, string formats, numeric ranges — and a validator checks whether your data conforms to it. JSON Schema is widely used for API request/response validation, form validation and config file checking.
How to Validate JSON Against a Schema
- 1Paste your JSON data into the left panel
- 2Paste your JSON Schema into the right panel
- 3The validator runs automatically and shows results below
- 4Fix any highlighted errors and re-validate in real time
Example
JSON Schema:
{
"type": "object",
"required": ["name", "age"],
"properties": {
"name": { "type": "string", "minLength": 1 },
"age": { "type": "number", "minimum": 0 },
"email": { "type": "string", "format": "email" }
},
"additionalProperties": false
}Valid JSON data:
{ "name": "Ravi", "age": 28, "email": "ravi@example.com" }Invalid JSON data (age is a string, unknown field present):
{ "name": "Ravi", "age": "twenty-eight", "role": "admin" }Supported Keywords
type
string, number, integer, boolean, array, object, null
required
Array of field names that must be present
properties
Define the schema for each named property
additionalProperties
Control whether extra fields are allowed
minLength / maxLength
String length constraints
minimum / maximum
Numeric value constraints (inclusive)
pattern
Regex pattern the string must match
format
email, uri, date, date-time, ipv4, uuid
enum / const
Restrict value to a specific set or single value
allOf / anyOf / oneOf
Schema composition and union types
if / then / else
Conditional schema application
items
Schema for array elements