Secure JSON Formatter & Type Generator - Local Type Gen

Secure JSON formatter: format, validate, and fix JSON locally. Beautify/minify, highlight errors, generate TypeScript or Zod, convert to XMLโ€”private. Try now.

Click for theater mode
JSON Input

Drop JSON/JSONC/NDJSON here โ€” parsed offline in your browser

Key Count

0

Nesting Depth

0

Duration

0.0ms

Paste JSON to start

How to Use

  1. Paste JSON into the editor, or drop a JSON/JSONC/NDJSON file.
  2. Choose an action: Format / Minify / Validate / TS / Zod / XML.
  3. Copy or download the output, or open the Diff to audit changes.
  4. If validation fails, fix the line/column hint and generate types again.

Core Features

  • Format JSON with pretty print for readability and review.
  • Minify JSON to reduce payload size for transport and storage.
  • Validate syntax and highlight the exact line/column of errors.
  • Generate TypeScript interfaces and Zod schemas from real JSON data.
  • Convert JSON to XML for legacy systems and integrations.
  • Compare changes with a Diff viewโ€”everything stays local and private.

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Calculation Logic

  • Parsing uses JSON.parse; rendering uses JSON.stringify.
  • Type generation walks objects/arrays recursively and maps fields to TS/Zod syntax.
  • Diff rendering can be built with an LCS-based text diff algorithm.
  • Heavy work can run inside a Web Worker to keep the UI responsive.

FAQ

  • Is it free? Any limits?
    • Yesโ€”formatting, validation, TS/Zod generation, XML conversion, and diff are free to use.
  • Is my data private? Do you upload JSON?
    • No uploads. Everything runs locally in your browser, including sensitive keys.
  • How do I convert JSON to TypeScript interfaces automatically?
    • Paste JSON and click TS to generate strict interfaces instantly.
  • Why does JSON.parse fail on โ€œvalid-lookingโ€ JSON? (Technical)
    • Common causes include trailing commas, unquoted keys, single quotes, comments (JSONC), or missing braces/brackets.
  • Why generate a Zod schema from JSON?
    • Zod adds runtime validation so your app can safely detect API shape changes.