JSONSchema
Turn sample JSON into a strict schema + validator.
JSONSchema turns a sample JSON object into a strict JSON Schema (draft 2020-12), explains each required field, and lists the validation rules your API should enforce.
Paste a sample JSON object and get a JSON Schema (draft 2020-12), a plain explanation of required fields, and the validation rules your API should enforce.
Input to output
- Sample JSON to JSON Schema
- Mark required fields automatically
- Explain each validation rule
- Draft 2020-12 compliant
Formats in and out
- Sample JSON to JSON Schema
- Auto required fields
- Draft 2020-12 compliant
How does JSONSchema build a schema?
Paste a sample JSON object and it infers a JSON Schema, marking required fields automatically and targeting the draft 2020-12 standard used by modern validators.
Does it explain the rules?
It explains each validation rule in plain language, so a developer knows what the API should reject without reading the schema spec line by line.
Why draft 2020-12?
Draft 2020-12 is the current JSON Schema standard most tooling supports, so the output drops into existing validators without version friction.
Who is JSONSchema for?
It fits API developers who want a strict, documented contract from a sample instead of hand-writing schema by hand.
When to do this manually
What JSONSchema does is narrow: Turn sample JSON into a strict schema + validator. A passing schema check only proves the data matches the contract you defined. It will not catch wrong business logic or bad data that still fits the shape.
Format questions
What is JSONSchema?
JSONSchema is a tool that turns a sample JSON object into a strict JSON Schema with explanations and validation rules.
What schema version does it use?
It produces JSON Schema draft 2020-12, the current standard most validators support.
Does it mark required fields?
Yes. It marks required fields automatically from the sample.
Does it explain the rules?
It explains each validation rule in plain language so you know what the API should enforce.
Who should use it?
API developers who want a strict, documented contract from a sample object.
Is it compliant with modern tooling?
Draft 2020-12 compliance means the schema works with current validators.
What inputs does JSONSchema struggle with?
Not a replacement for proper testing, CI, and code review. Validate generated code, schemas, and regexes against your real inputs before shipping.
Who is JSONSchema for?
API and data teams reach for JSONSchema when the job is: Turn sample JSON into a strict schema + validator.
Built by Xingliang Li · LX Micro-SaaS Factory — a one-person, curated set of tight-vertical AI tools. How tools are selected →