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Format, validate, tree-view, schema-gen, type-gen, diff. 100% browser-side.
Format, validate, explore, generate types, infer schemas, and diff documents, all in one tool, all in your browser. Your JSON never leaves the tab.
Drop a .json file, paste from clipboard, or type. Up to 50 MB. Everything runs in your browser.
Pretty-print or minify, view as a live tree, hover any node to copy its JSONPath.
One click to a TypeScript interface, Zod schema, Go struct, or full JSON Schema (draft-2020-12).
Indent with 2 spaces, 4 spaces, or tabs. Minify to a single line for embedding. Round-trip safe, so your input is never lossy-modified.
Errors point to the exact line and column. Common JS-vs-JSON mistakes (single quotes, trailing commas, comments, unquoted keys) get one-click auto-fix.
Navigate huge documents. Hover any node and click to copy a JSONPath like $.users[0].address.zip. No competitor on page-1 of Google has this.
Auto-derive a draft-2020-12 JSON Schema from any sample. Detects formats (date, email, URL, UUID), required fields, array element types. Ready for AJV, OpenAPI, or contract tests.
TypeScript interface, Zod schema, or Go struct from any JSON sample. Use it to type API responses, generate boilerplate, or document a contract.
Side-by-side compare with added / removed / changed paths. Order-independent for objects, position-aware for arrays. Perfect for API regression testing.
Size, max nesting depth, and total node count update as you type. Catch ballooning payloads before you ship them.
JSON.parse runs locally. Your data is never uploaded, never logged, never seen by us. The page works offline after first load.
Most free formatters ship your JSON to a server for processing. Some ad-supported sites log your inputs. We do not. The whole tool is a browser bundle. Close the tab and the data is gone.
Unlimited use. No signup. No watermark. JSONLint shows ads, JSONFormatter has size limits, JSONFormatter.curiousconcept.com makes you sit through interstitials. We don't.
Tree explorer with click-to-copy JSONPath, JSON-Schema generator, and TypeScript/Zod/Go converter, all in one tool. Most competitors do one or two and ad-gate the rest.
Handles the JS-vs-JSON gotchas that frustrate users: trailing commas, single-quoted strings, unquoted keys, comments, undefined values. Auto-fix in one click, no manual hunt.
| Feature | Molixa JSON Formatter | JSONFormatter.org | JSONLint |
|---|---|---|---|
| Free tier | Unlimited, no signup | Ad-supported, capped | Ad-supported |
| Privacy | 100% browser-side | Server-processed | Server-processed |
| Tree explorer | Yes, click-to-copy JSONPath | Static collapse only | No tree |
| JSON Schema generator | Yes, draft-2020-12 | Paid tier | No |
| TypeScript / Zod / Go types | Yes, all three | No | No |
| Diff two documents | Yes, built in | Separate tool | No |
| Auto-fix JS-isms | Yes, one click | No | No (errors only) |
| File size limit | 50 MB | 5 MB free | 1 MB |
| Works offline | Yes, after first load | No | No |
Paste the response, instantly spot the structure, copy a JSONPath to file in your bug ticket.
Drop a sample response from the backend, get a TypeScript interface or Zod schema, paste into your client code.
Run the schema generator to produce a JSON Schema. Commit it next to the config so editors validate as you type.
Paste yesterday's API response and today's. The diff tool shows exactly what changed and where.
Paste the raw body. Catch malformed payloads before they crash your handler. Fix common JS-isms with one click.
Run the type generator + schema generator together. Get types, validation, and documentation in 30 seconds.
The entire tool runs as a single browser bundle. JSON.parse, the formatter, the validator, the tree explorer, the schema generator, and the type converter all execute locally. There is no API call, no server upload, no log of your input. Close the tab and your data is gone.
That matters when you're pasting payloads with API keys, customer records, internal IDs, or anything else you don't want a third party to see. It also means the tool works offline once the page has loaded, which is handy for airplanes, locked-down corporate networks, or air-gapped environments.
Debug API payloads, generate types from sample responses, validate config files.
Type API responses with Zod or TypeScript, navigate deeply nested data, copy JSONPath for tests.
Diff config drift, validate webhook payloads, generate JSON Schema for contract tests.
Reproduce API regressions with the diff tool, document exact paths in bug reports, validate response shapes.
No signup, no daily cap, no watermark. Drop in a 50 MB file or paste from your console. Generate types, schemas, and diffs without leaving the page.
Start formattingThe JSON Formatter & Validator page is built, reviewed, and maintained by the Molixa team. We use the tool we ship and update the docs when the behavior changes.