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Validate JSON Formatter

Validate JSON fast, get a readable error (with line/column when available), and format your JSON as pretty-printed or minified output. Works fully in your browser—no uploads.

Category: Data · URL: /tools/validate-json-formatter.html
No network calls. Runs locally.
Input JSON0 chars
Output0 chars
Related: Pretty Print Formatter (JSON, XML, SQL) CSV Format Checker Free CSV Tool Online SQL Generator SQL Formatter for VSCode Online Normalize Generator Pixels ↔ DPI ↔ Print Size Online Normalize Generators
Privacy: runs locally in your browser. No uploads, no tracking scripts.

How to use

Use this tool to validate and format JSON safely in your browser.

  1. Paste your JSON into the input box.
  2. Choose Indent (2, 4, or tab) and optionally enable Sort keys.
  3. Click Validate + Pretty or Minify.
  4. If invalid, read the error and jump to the reported position.
  5. Copy the formatted output when it looks right.
Keywords this page targets (natural cluster): validate json, json validator, validate json formatter, json formatter, pretty print json, minify json, json lint, json syntax checker, find json error line, json parse error position, format json online, sort json keys, json beautifier, compact json, check if json is valid, json error message, validate json array, validate json object, escape json checker, json viewer, json indentation formatter
Secondary intents covered: Check whether a JSON string is valid before using it in an API, Locate the exact line/column of a JSON syntax error, Pretty print JSON for readability with a chosen indent size, Minify JSON to reduce size for storage or transport, Sort object keys to get stable, diff-friendly JSON output, Copy formatted JSON to clipboard for pasting into code/config files, Confirm JSON is an object/array/value and see quick size stats, Remove BOM/whitespace issues that can break JSON parsing

FAQ

Is my JSON uploaded to a server?

No. The validator runs locally in your browser; nothing is sent over the network.

Why does it say “Invalid JSON” when it looks close to correct?

JSON is strict: keys and strings must use double quotes, and trailing commas are not allowed.

Can it show the exact error location?

Yes when the browser provides an error position; the tool converts it to line/column and shows a snippet with a caret.

What does “Sort keys” do?

It recursively sorts object keys alphabetically to produce stable, diff-friendly output; array order is preserved.

Does minify change the JSON meaning?

No. Minify only removes whitespace; the parsed value stays the same.

Can it validate top-level values like numbers or strings?

Yes. Valid JSON can be an object, array, string, number, true/false, or null.

Why did key order change after formatting?

If “Sort keys” is enabled, key order is intentionally rearranged; otherwise order usually follows the parsed object’s insertion order.