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JSON Schema Validator

Validate JSON payloads against JSON Schema drafts using Ajv with configurable strictness, coercion, and error reporting — all offline in your browser.

JSON Schema

JSON Data

Validation Report

Output will appear here

Format: markdown

How It Works

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Provide Schema & JSON Payload

Paste or upload your JSON Schema on the left and the JSON document you want to validate on the right. Leave the payload empty to validate the schema alone.

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Configure Validation Rules

Toggle allErrors, type coercion, additional property handling, and strict mode to match your environment or API contract expectations.

Run Ajv Validation Instantly

Validation executes locally via Ajv, returning readable summaries with instance paths, failing keywords, and contextual parameters for each issue.

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Export or Share Results

Copy the formatted report, download the results, or store the run in tool history for audit trails, QA reports, or regression test artifacts.

Problems It Solves

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Problem

Schema mismatches reach production because teams lack a quick way to validate JSON payloads against updated contracts.

Solution

Catch contract violations before deploys with instant, browser-based Ajv validation that highlights failing paths and keywords.

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Problem

Maintaining strict schemas across microservices is difficult when optional features rely on different validation rules.

Solution

Toggle Ajv options like allowUnionTypes, removeAdditional, and strict mode per environment to mirror staging and production behavior.

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Problem

Debugging Ajv errors can be cryptic when instance paths and params are buried in the console.

Solution

Readable error summaries with instance paths, keyword context, and structured metadata make triaging validation failures fast for any teammate.

Why Choose This Tool

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Powered by Ajv

Leverages the industry-standard Ajv validator with configurable drafts and options, so results match modern backend implementations.

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Privacy-First Validation

Schemas and payloads never leave your browser, making it safe for regulated data and pre-release APIs.

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Actionable Reporting

Readable Markdown output, structured metadata, and history tracking help teams document issues and automate regression checks.

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Developer-Friendly UX

Dual editors, copy/download helpers, and auto-validation keep productivity high when iterating on schemas or onboarding teammates.

Frequently Asked Questions

Which JSON Schema drafts are supported?
Ajv supports draft-04 through draft-2020-12. Provide a $schema property in your schema to target a specific draft when needed.
Can I validate without providing data?
Yes. Leave the data panel empty to validate only the schema structure and catch compile-time issues.
What does removing additional properties do?
It strips properties not defined in the schema. Use with caution if you need to surface unexpected fields instead of silently dropping them.
How do I validate multiple documents?
Run each JSON instance individually or paste an array of objects if your schema expects an array. The validator processes exactly what you provide.
Does the tool send my data anywhere?
No. Validation runs entirely in your browser using Ajv, so schemas and payloads never leave your device.