English

Developer tool

Format, validate, minify, and compare JSON

Pretty-print, minify, and validate JSON, or compare two JSON documents to find added, removed, and changed values. Everything runs in your browser.

Tidy or compress JSON, check syntax errors, and compare two JSON documents for added, removed, or changed values. Nothing is sent to NEXNARA.

  • Runs locally
  • No uploads
  • Instant
  • Free
Mode

Files stay in this browser. Nothing is uploaded to a server.

How it works

  1. Paste your data
  2. Run the action
  3. Copy the result

Why NEXNARA

  • Private

    Your data stays in your browser.

  • Instant

    Results appear immediately.

  • No uploads

    Nothing is sent to a NEXNARA server.

  • Works anywhere

    No installation required.

Format and validate JSON

A JSON formatter checks whether text is valid JSON, then can print it with indentation or as a compact one-line string. This page also compares two JSON documents. It uses JSON.parse and JSON.stringify in your browser and never uses eval.

Format and validate JSON

Paste JSON to pretty-print it, minify it, or check the syntax. Formatting does not change keys or values beyond what JSON.stringify already does.

Pretty print JSON

Pretty print adds line breaks and indentation so nested objects are easier to read. Choose 2 spaces, 4 spaces, or tabs. The default is 2 spaces.

Minify JSON

Minify removes extra whitespace and line breaks while keeping spaces inside strings. The data stays the same; only the packaging gets smaller.

Find invalid JSON

Typical issues include trailing commas, single quotes, comments, or unquoted keys. When the browser reports a location, this tool shows the line, column, or character position. It does not invent a location.

Compare two JSON documents

JSON Diff parses both sides, then lists added, removed, changed, and type-changed paths. Pretty JSON and minified JSON with the same content are treated as equal.

Added and removed fields

A path that exists only in JSON B is Added. A path that exists only in JSON A is Removed. Missing is not the same as null.

Changed values

When the same path has a different value of the same type, the row is Changed and shows the old and new values. A string such as "100" versus the number 100 is Type changed.

Nested JSON differences

Objects are compared recursively. A change inside user.address.city is reported at that path, not as a whole-object replacement.

How arrays are compared

Arrays are compared by index: items[0], items[1], and so on. Reordering items can produce several diffs. This tool does not try to match array items by a hidden id.

How to use it

Use Format & Validate to tidy, compress, or check one JSON document. Use JSON Diff to paste or upload two documents, then compare. Load example shows a small sample with added, removed, changed, and type-changed values.

Privacy

Your JSON stays in the browser. It is not uploaded to NEXNARA servers and is not saved in cookies, local storage, or a database.

FAQ

What does a JSON formatter do?

It checks that the text is valid JSON, then can reprint it with indentation or as a compact string. The data stays the same.

How do I validate JSON?

Paste the text and tap Validate JSON. Valid input shows a success state. Invalid input shows a clear error and, when the browser provides it, a line, column, or position.

Can I minify JSON?

Yes. Minify JSON removes extra whitespace and line breaks. Spaces inside strings are kept.

How do I compare two JSON objects?

Open JSON Diff, paste or upload JSON A and JSON B, then tap Compare. The table lists added, removed, changed, and type-changed paths.

Does key order matter?

No. Object key order alone is not treated as a difference. {"a":1,"b":2} and {"b":2,"a":1} are the same.

How are arrays compared?

By index. items[0] is compared with items[0]. If you only reorder items, several rows may change. There is no key-based array matching in this version.

Can I compare nested JSON?

Yes. Nested objects are walked recursively, so a change is shown at a path such as user.address.city.

What is the difference between missing and null?

A missing field is Removed or Added. null is a real JSON value. null, "", 0, and false are not treated as the same.

Is my JSON sent to a server?

No. Parsing, formatting, and comparison run locally in your browser. Files you choose are not uploaded.

How large can the JSON be?

Typical documents with thousands of keys are fine. You get a warning above 5 MB. Documents larger than 15 MB are blocked so the browser stays responsive.

Related Stories