Why a JSON Formatter Saves Time

JSON Formatter (Advanced): format, validate, diff, and generate types

When you’re debugging an API response, reviewing a config file, or sharing data with a teammate, raw JSON is painful to scan. A good JSON formatter should do more than indent—it should help you find errors, compare versions, and even generate types.

This guide walks through the advanced features of our JSON Formatter tool (formatting, validation, schema checks, diff, code generation, exports, and snippets).

Open the tool

Use the JSON tool here (adjust slug if you changed it): /tools/json-formatter.

1) Format and minify JSON

• Format turns minified JSON into readable JSON with indentation.
• Minify produces a compact one‑line JSON output for logs and APIs.
• Sort keys makes output stable (helps code reviews and diffs).

Example input:

Formatted output:

2) Validate JSON (Problems panel)

The Problems tab shows syntax errors with exact line/column locations.

Common mistakes:

• Trailing commas
• Single quotes instead of double quotes
• Missing braces or brackets

3) JSONC mode (comments + trailing commas)

If you’re working with “JSON with comments” (common in configs), switch to JSONC mode, then use Convert to strict to produce valid JSON.

4) Validate against JSON Schema

Enable Schema validation to validate configs like:

• package.json
• tsconfig.json

You can also paste your own custom JSON Schema to validate internal API payloads.

5) Compare two JSON documents (Diff)

Use the Diff tab to compare left vs right JSON.

Tip: enable Semantic diff to compare formatted + sorted JSON so key ordering doesn’t hide real changes.

6) Generate TypeScript types, Zod schema, and JSON Schema

The Codegen tab generates:

• TypeScript types for DTOs
• Zod schema for runtime validation
• JSON Schema for documentation and contract testing

This is useful when you have a sample API response and want strongly typed code fast.

7) Export helpers and integration recipes

Export options include:

• Copy current JSON
• Download .json
• Copy as JSON string
• base64url encode/decode (handy for URLs/env vars)

Integration recipes are included for Node.js, Python, browser, and jq.

8) Save reusable snippets (local + account)

Use Snippets to save repeated JSON payloads:

• Local snippets: stored in your browser
• Account snippets: save to your account (sync across devices) and optionally enable share links

Summary

This JSON Formatter is designed as a full workflow tool: format + validate + diff + schema + codegen + snippets—while keeping privacy in mind by running locally in the browser.