JSON formatting, repair, diff and schema work in one browser tab.

Paste API payloads, webhook bodies, config files or NDJSON logs. Everything runs client-side unless you explicitly copy data elsewhere.

JSON and NDJSON JSON Pointer RFC 6901 JSON Patch-style diff Local history
Input
Ctrl+Enter formats. Tab inserts indentation.
Client-side
Workbench
Formatted output
0 BPayload size
0Values and containers
0Maximum nesting depth
0Arrays found
Reference Notes
Stable references used while redesigning this tool.
JSON.parse and JSON.stringify

Native browser parsing and stringifying are used for validation, formatting and minification.

MDN JSON.parse
JSON Pointer

Pointer queries use RFC 6901 escaping rules for slash and tilde characters.

RFC 6901
JSON Patch

The diff tab emits add, remove and replace operations shaped like RFC 6902 patch entries.

RFC 6902
JSON Schema

Schema inference outputs a draft 2020-12 starter schema that should be reviewed before production use.

JSON Schema

JSON Formatter & Validator FAQ

How should I use this?

Paste JSON, format or repair it, inspect errors, run a pointer query, infer schema or types, then copy or download only the output you intend to share.

What does redacted copy mask?

It masks common secret fields such as tokens, passwords, API keys, authorization values, email addresses, and phone fields. Review manually before sharing.

Is this a production validator?

No. It is a local browser utility. Compare the result against your OpenAPI, JSON Schema, backend tests, or provider documentation.

Developer safety check

Validate structure before sharing payloads

Use formatting, repair, pointer queries, schema/type inference, diffing, copy, and download as a local API-debugging workflow.

Runs in browser

Payloads are not uploaded by the formatter itself.

What to check

  • Methodology: parse the payload locally, render the selected mode, then compare schema, type, query, or diff output against your real contract.
  • Verify parse status, required fields, date formats, array depth, null handling, and schema or TypeScript fit against the real API contract.
  • Remove tokens, passwords, keys, personal data, and production identifiers before copying output into tickets or docs.
  • Use download only for sanitized examples that are safe to store locally.

Limitations

  • Disclaimer: local utility only, not an official schema validator, security scanner, or production API guarantee.
  • Repair and type inference are best-effort helpers; review generated schema/types before committing code.
  • Local-first privacy depends on not pasting sensitive payloads into external chats, logs, or shared screenshots.
Review formatter output

Source/reference note: compare against your current OpenAPI, JSON Schema, backend tests, or provider documentation before shipping changes.