JSON Formatter

• Human-readability: indentation and line breaks make JSON easier to understand.
• Easier debugging: errors stand out when JSON is properly formatted.
• Save time instead of trying to format with manually written code.
• Secure and can work offline once loaded. Runs in your browser, so your data is not sent to a server.

• Pretty-print: Beautifies and formats JSON data with selectable indentation (2 spaces, 4 spaces, or Tab).
• Minify: Compacts JSON to a single line with no whitespace via the "Minified" indentation option.
• Key Sorting: Optionally sorts object keys alphabetically for consistent output.
• Syntax validation: Validates strict JSON syntax with detailed error messages, the exact line and column, and a “Go to error” jump that highlights the offending character in your input.
• JSON Schema validation: Optionally validates strict raw JSON against Draft 7 or Draft 2020-12. The schema draft is auto-detected from $schema (Draft 7 is the fallback), local fragment references are supported, and the first violation includes its JSON Pointer, rule, message, and source line/column.
• Auto Fix: Auto-fixes common JSON errors and is enabled by default.
• Copy to clipboard / Download: Copy formatted output with confirmation or download it as a .json file.
• Syntax highlighting: Color-coded keys and values improve readability in tree view.
• Tree Node Expand/Collapse: Expand or collapse nested objects and arrays while preserving structure, with Expand All / Collapse All controls.
• Size Comparison: Real-time size updates support bytes, KB, MB, and GB with accurate formatting.
• Shareable URLs: Click “Share” to copy a link with your JSON and settings compressed into the URL’s hash fragment, so it never leaves your browser.
• Local file input: Click Upload File or drag a text file into the input; files are read in the browser and never uploaded.

1. Enter JSON Data

   Paste your JSON string into the input area, click "Upload File" to choose a local text file, or use the "Load Sample" button if you are just trying out the tool.

2. (Optional) Update Configuration

   Toggle the "Auto fix" checkbox to enable or disable automatic error correction, toggle "Sort keys" to enable or disable key sorting, pick an "Indent" option (2 spaces, 4 spaces, Tab, or Minified), and optionally expand JSON Schema validation to paste or upload a schema and choose a draft.

3. Validate and Format

   Click "Format JSON" when no schema is present, or "Format & Validate" after adding a schema. Syntax validation always runs; schema validation then checks strict raw JSON against the selected or auto-detected Draft 7 or Draft 2020-12 schema.

4. Pick your preferred result view

   Switch between tree view and plain text to inspect the formatted JSON the way you prefer.

5. Copy formatted JSON

   Click "Copy Output" to copy the result after the tool confirms the operation succeeded.

6. Handle errors

   If the JSON is invalid, the input is preserved and the error message indicates the issue so you can fix it quickly.

Example Input:

{"z":1,"a":{"d":2,"c":3},"b":[4,3,2]}

Example Output:

{
  "a": {
    "c": 3,
    "d": 2
  },
  "b": [
    4,
    3,
    2
  ],
  "z": 1
}

• Large JSON files may impact performance.
• Schema validation accepts Draft 7 and Draft 2020-12 only, with a 256 KiB schema limit, maximum schema depth of 100, and a five-second worker deadline.
• Schema validation uses strict raw JSON. If Auto fix was needed to format the source, validation reports that it was not run until the source is valid JSON.
• Only fragment-local $ref, $defs, and definitions are supported. External references are rejected without network requests.
• The JSON Schema format keyword is treated as annotation only; it is not asserted.
• The tool currently does not sort array elements and only sorts object keys.
• Clipboard operations require a secure context such as HTTPS or localhost.
• Does not preserve trailing commas.
• Unicode characters in strings are not escaped or unescaped.
• No support for JSON5 or JSON with comments (JSONC).
• The auto-fix feature is not a full JSON5 parser and may not fix all syntax errors.

This JSON Formatter Tool provides specific error messages for common JSON syntax errors and, when a schema is supplied, the first actionable schema violation:

• Missing or extra commas
• Unclosed brackets or braces
• Invalid property names
• Missing colons
• Invalid values

You will see syntax errors below the input area, including the line and column where the tool detected the issue. Schema diagnostics show the JSON Pointer, rule, message, and source line/column; use the jump action to select that location. Invalid schemas, unsupported drafts, external references, limits, and unavailable workers are reported without removing formatted output.

• 100% client-side processing: JSON formatting and JSON Schema validation happen in your browser.
• No tool-side storage or upload: JSON and schema text are not saved or transmitted by this formatter.
• Offline support: formatting works without an internet connection once loaded; schema validation works after its lazy validator chunk has loaded.
• Schema privacy: schema text and draft selection are not persisted and never appear in Share links.
• Private sharing: the “Share” link stores only JSON and formatter settings in the URL’s hash fragment, which browsers never send to a server.

• Modern Browsers: Chrome, Firefox, Safari, Edge
• Requirements: JavaScript enabled
• Copy functionality: Primary support comes from the modern Clipboard API on HTTPS or localhost, with execCommand fallback for older browsers or HTTP contexts.
• Mobile Support: Fully responsive design with touch-friendly controls.

Please contact us for any bug report, feature request, or feedback.

What is a JSON Formatter?

A JSON Formatter is an online tool that takes unformatted or minified JSON data and beautifies it by adding proper indentation and line breaks. This makes the JSON much easier for humans to read and debug.

How do I pretty-print JSON?

To pretty-print JSON, you can use an online JSON Formatter. Simply paste your JSON and click the format button. The tool will output a nicely indented JSON structure with sorted keys and highlighted syntax for easy reading.

Is an online JSON formatter safe to use?

Yes - as long as the formatter runs in your browser (client-side), your JSON data is not sent anywhere, making it safe. The CodeSamplez JSON Formatter Tool processes JSON locally, so your sensitive data never leaves your computer.

Can a JSON Formatter also validate JSON?

Yes. The formatter always checks JSON syntax, and its optional JSON Schema validation checks whether valid data matches a contract. Open the JSON Schema validation disclosure to use Draft 7 or Draft 2020-12; the tool reports the first schema issue with its JSON Pointer and source line/column. Auto fix can format repaired output, but schema validation waits until the original input is strict JSON.

How do I fix "Unexpected token" errors in JSON?

An "Unexpected token" error means the parser hit a character it did not expect at that position - usually a stray comma, an unquoted key, single quotes instead of double quotes, or a missing bracket. Paste the JSON into this tool and click "Format JSON"; the validator reports the exact line and column, and "Go to error" jumps straight to the offending character so you can fix it.

What is the difference between JSON, JSON5, and JSONC?

JSON is the strict standard: double-quoted keys and strings only, no comments, and no trailing commas. JSON5 extends it with comments, trailing commas, unquoted keys, and single-quoted strings for easier hand-editing. JSONC ("JSON with Comments") is plain JSON plus // and /* */ comments, commonly used in editor config files like tsconfig.json. This tool parses strict JSON, so JSON5 or JSONC input should be converted to JSON first.

Is it safe to paste API keys or secrets into an online JSON formatter?

With this tool, yes - all formatting and validation happens entirely in your browser via JavaScript, and no JSON you paste is ever sent to a server. That said, avoid pasting secrets into formatters you have not verified are client-side, since some tools upload input for server-side processing.

How do I format JSON in VS Code or the terminal vs. online?

In VS Code, select the JSON and press Shift+Alt+F (Shift+Option+F on macOS), or right-click and choose "Format Document". In a terminal, pipe it through a tool like "python -m json.tool" or "jq .". An online formatter like this one needs no install, works on any device, and adds features like tree view, key sorting, and error highlighting that most editors and CLI tools do not.

How do I minify JSON, and why minify it?

To minify JSON with this tool, choose the "Minified" indentation option and click "Format JSON" - the output collapses to a single line with no extra whitespace. Minifying reduces payload size for network transfer and storage, which matters for API responses and config files where every byte counts; pretty-printed JSON is for humans, minified JSON is for machines.

What does a "trailing comma" or "expected property name" JSON error mean?

Browsers word this error differently (for example "Expected property name or '}'" in Firefox, or "Expected double-quoted property name" in Chrome), but the cause is the same: the parser expected a quoted property name or a closing brace at that position and found something else instead - commonly a trailing comma before a closing brace (e.g. {"a":1,}) or a missing key. Enable "Auto fix" before formatting to have the tool correct common cases like trailing commas automatically, or use "Go to error" to jump to the exact spot and fix it manually.

Is sharing a JSON Formatter link private?

Yes. Clicking "Share" compresses your JSON and formatter settings and puts them in the URL's hash fragment (the part after #), which browsers never send to a server. JSON Schema text and the selected draft are intentionally not persisted or included in shared URLs.