JJSONForge
JSON toolkit

JSON, finally tamed.

Format, diff, validate and generate Schema from sample — without ever leaving the browser or pasting JSON into sketchy free tools.

Plans from $5/mo — cancel any time

Paste JSON
Formatted / Diff / Schema

Everything a backend team paste-debugs

Built for engineers wiring up APIs, debugging webhooks, and reading 5 MB JSON dumps.

Lightning-fast format

Pretty-print or minify multi-megabyte JSON without freezing the tab. Tree view, line numbers, fold by key.

Two-payload diff

Paste two JSON blobs side-by-side — JSONForge highlights every added, removed, or changed key. Works on deeply nested structures.

JSON Schema validator

Paste a schema + a payload. Pass / fail / per-property errors. Supports JSON Schema draft 2020-12.

Schema from sample

Drop a sample JSON. Get a clean JSON Schema you can paste into your API spec or backend validation library.

Path query

JSONPath / JMESPath built in. Test selectors on real data before you ship them to production.

Private by design

Everything runs in your browser. Your JSON never touches a server unless you choose to save it.

Three steps

From a wall of JSON to a clean view of what changed or what failed.

1

Paste

Drop in your JSON — single payload or two for diff.

2

Pick a tool

Format, validate, diff, or generate Schema.

3

Ship

Copy the result straight into your code or your docs.

Simple pricing

Pick a plan and stop pasting into random websites.

Starter

For solo backend engineers

$5/mo
  • 200 saved documents / mo
  • Full format, diff, validate
  • Schema from sample (500/mo)
  • Unlimited path queries
Most popular
Pro

For platform teams

$15/mo
  • 5000 saved documents / mo
  • Bulk Schema-from-sample (20k/mo)
  • Team-shared library
  • API for CI integration
  • Priority support

Frequently asked

Does my JSON leave my browser?

No. Format / diff / validate / Schema-from-sample all run client-side. Only saved documents (opt-in) are persisted server-side.

How big a payload can it handle?

Comfortably 10–20 MB on modern laptops. We stream-parse so the tab stays responsive even on huge files.

Which Schema draft do you support?

JSON Schema 2020-12 plus backward-compat with draft-07 and draft-06. We mark unsupported keywords clearly in the validator output.

Do I get a free trial?

No — JSONForge is a paid tool starting at $5/mo. The demos on this page show exactly what you get.

How do I cancel?

From the account page, or by emailing us. Cancellation stops the next renewal — your remaining time stays usable.

Stop pasting JSON into random tools.

Format, diff, validate, ship.

See plans