Every JSON problem, one platform
Validate, repair, diff, secure, and document JSON — 32 tools free forever, with Pro-grade analysis for teams shipping APIs at scale. Start free, no card required.
Every tool, live
32 JSON tools, all free, all running entirely in your browser.
Core tools
JSON Formatter
Beautify or minify JSON with your choice of indentation.
JSON Repair
Automatically fix broken JSON and see exactly what changed.
JSON Viewer
Explore JSON as a collapsible, color-coded tree.
JSON Tree View
Explore JSON as a collapsible, color-coded tree.
JSON Diff
Compare two JSON documents and see exactly what changed.
JSON Escape
Escape plain text into a valid JSON string literal.
JSON Unescape
Unescape a JSON string literal back into plain, readable text.
JSON Sort Keys
Sort every object key alphabetically, at every depth.
JSON Flatten
Flatten nested JSON into dot-notation keys.
JSON Unflatten
Rebuild nested JSON from flattened dot-notation keys.
JSON Search
Search for a key or value anywhere inside a JSON document.
JSON Merge
Deep-merge two JSON documents into one.
JSON Secret ScannerPro
Scan JSON for API keys, tokens, and other secrets before you share it.
JSON SanitizerPro
Redact sensitive fields before sharing a JSON sample.
JSON Complexity AnalyzerPro
Spot deeply nested structures, huge arrays, and oversized payloads.
JSON Payload OptimizerPro
See how much smaller your JSON payload could be.
JSON Field Mapper
Rename JSON keys throughout a document using a mapping table.
JSON Documentation GeneratorPro
Generate a Markdown field reference from a JSON sample.
JSON Field Usage HeatmapPro
See which fields actually show up across many JSON records.
JSON API Contract Checker
Check whether an API response matches its expected shape.
JSON Health ScorePro
A single 0-100 quality score for any JSON document.
Semantic DiffPro
Compare JSON by meaning, not just characters — and know if it's a breaking change.
Converters
JSON to CSV
Convert JSON arrays and objects into spreadsheet-ready CSV.
JSON to XML
Convert JSON into clean, indented XML.
JSON to YAML
Convert JSON into clean, readable YAML.
JSON to TypeScript
Generate TypeScript interfaces from a JSON sample.
JSON to Zod Schema
Generate a Zod validation schema from a JSON sample.
JSON to Python
Convert JSON into a Python dict literal.
JSON to Java
Generate a Java POJO class from a JSON sample.
JSON to SQL
Generate CREATE TABLE and INSERT statements from JSON.
API Mock Generator
Generate realistic fake JSON records matching a sample shape.
Why developers use JSONValidator.in
Line-accurate errors
Every syntax error is pinpointed to an exact line and column, not just a vague message.
Plain-language explanations
Errors are translated from cryptic parser output into a clear description of what's wrong.
Handles large documents
Validate deeply nested or multi-megabyte JSON without the tab freezing.
100% client-side
Your JSON never leaves your browser — nothing is uploaded to a server.
Frequently asked questions
Free forever. Pro when you need it.
All 32 core tools are free, no account needed. Pro unlocks advanced analysis — 7-day free trial, no card required.
Free
Free
Every validator, formatter, and converter — free, forever.
Starter
$10/mo
For solo developers who want the advanced analysis tools.
Pro
Pro$35/mo
For small teams shipping APIs who need this in their workflow.
Business
$100/mo
For larger teams standardizing on JSON quality tooling.