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JSON tools

Format, validate, compare and convert JSON, YAML and CSV data. Every tool runs in your browser, so nothing you add is uploaded.

Format & validate

Make JSON readable or compact, and find exactly where and why it is invalid.

JSON Formatter

Formats messy or minified JSON into clean, indented, readable text, and points out any errors.

JSON Validator

Checks whether JSON is valid and explains each error in plain language, with its exact line and column.

JSON Minifier

Removes all unnecessary spaces and line breaks from JSON to make it as small as possible.

Convert

Move data between JSON, YAML and CSV, and generate TypeScript or Zod definitions from examples.

CSV to JSON

Converts CSV spreadsheets into JSON, using the header row for property names and detecting numbers.

JSON to CSV

Converts a JSON array into a CSV file for Excel or Google Sheets, flattening nested objects.

JSON to TypeScript

Generates TypeScript interfaces from a JSON example, including nested objects, arrays, optional and nullable fields.

JSON to YAML

Converts JSON into clean, readable YAML for configuration files, Kubernetes and CI pipelines.

YAML to JSON

Converts YAML to JSON, reporting indentation and syntax errors with their exact line.

JSON to Zod

Generates Zod validation schemas from example JSON, detecting optional, nullable and nested fields.

Compare

Find every changed value between two JSON documents, ignoring key order and formatting.

JSON Diff

Compares two JSON documents by their data, listing every added, removed and changed value by path.

About JSON tools

Tools for working with JSON data: pretty-print and validate it with plain-English error messages, compare two documents, convert between JSON, YAML and CSV, and generate TypeScript types or Zod schemas from an example API response.

Because everything runs in your browser, you can paste real API responses, configuration files and customer data without sending them to a third party. Numbers are kept exactly as written, so large IDs are never rounded.

Frequently asked questions

Is it safe to paste API responses containing personal data?

Yes. The JSON is processed in your browser and never uploaded, logged or stored.

Why do some online formatters change my numbers?

JavaScript can only store numbers up to about 9 quadrillion exactly, so tools that parse and re-print JSON round larger IDs. The JSON Formatter here copies numbers exactly as written.

Do these tools accept JSON with comments or trailing commas?

They check strict JSON, as APIs expect, and point out comments and trailing commas as errors with a hint on how to fix them.