JSON Formatter
Format, beautify, and validate JSON with syntax highlighting, a collapsible tree view, auto-fix for trailing commas and single quotes, search, and JSON-to-XML/CSV/YAML conversion.
Why Use JSON Formatter?
Every developer has pasted a 40 KB minified API response into their terminal and squinted at a single-line wall of JSON. A good formatter does more than `jq .` — it color-codes types, flags the exact line where a trailing comma killed your parse, and shows a tree view you can collapse when only one section matters. Running locally (rather than on "jsonformatter.org" with an ad banner and a server round-trip) keeps sensitive tokens, PII, and customer data out of third-party logs. The auto-fix is the real time-saver: it repairs the trailing commas and single quotes that crop up constantly when copying JSON from JavaScript source files.
How to Use JSON Formatter
- Paste your JSON into the input panel, drag & drop a .json file, or click Upload to import from your device.
- Click 'Format' to beautify with syntax highlighting, 'Minify' to compress, or 'Fix JSON' to auto-repair common errors like trailing commas and single quotes.
- Switch between Code view (with color-coded syntax) and Tree view (interactive expandable/collapsible hierarchy) to explore your data.
- Use 'Convert' to transform JSON to XML, CSV, or YAML format. Download or copy the output when ready.
- Toggle 'Auto' mode to format on paste, use Search to find keys/values, and check the Statistics panel for data insights.
Worked Examples
Pretty-print a minified API response
{"users":[{"id":1,"name":"Jane"},{"id":2,"name":"Bob"}]}{\n "users": [\n { "id": 1, "name": "Jane" },\n { "id": 2, "name": "Bob" }\n ]\n}Switch to Tree View to collapse the users array and focus on metadata.
Auto-fix JSON with trailing commas
{ name: 'jane', roles: ['admin', 'editor',], }{\n "name": "jane",\n "roles": ["admin", "editor"]\n}Quotes added to keys, single quotes converted to double, trailing commas stripped.
Convert a config response to YAML
{ "server": { "port": 8080, "host": "0.0.0.0" } }server:\n port: 8080\n host: 0.0.0.0
Useful when dropping a JSON config into a Kubernetes or GitHub Actions YAML file.
About JSON Formatter
A JSON formatter is an online tool that takes raw or minified JSON data and formats it with proper indentation, syntax highlighting, and validation to make it human-readable. The JSON Formatter is a professional-grade JSON toolkit for developers. Beyond basic formatting and validation, it offers syntax highlighting with color-coded keys, strings, numbers, booleans, and nulls. The interactive tree view lets you explore JSON hierarchies with expand/collapse controls, type badges, and click-to-copy JSON paths. The auto-fix feature intelligently repairs common JSON errors including trailing commas, single quotes, and unquoted keys. Convert JSON to XML, CSV, or YAML with a single click. Upload JSON files via file picker or drag-and-drop, and download formatted output. The statistics panel shows key counts, nesting depth, data type distribution, and file size. Auto-format mode processes JSON on paste, and the search feature highlights matching keys and values across both code and tree views. Your data is saved locally between sessions, and all processing happens 100% client-side — no data ever leaves your browser.
Troubleshooting & Common Issues
"Unexpected token in JSON at position N"
The error message points to the byte offset where the parser gave up. Common causes: a stray trailing comma after the last element, a single quote instead of a double quote, or an unquoted key. Click "Fix JSON" to attempt an auto-repair or jump to the reported position manually.
Numbers like `1.0000000000001` render differently after format
JavaScript parses JSON numbers as IEEE 754 doubles, which lose precision beyond 15 significant digits. Large IDs (Twitter/X snowflake IDs, Unix nanosecond timestamps) should be serialized as strings, not numbers. If precision matters, fix it at the source.
Tree view is empty after successful parse
The root of the JSON must be an object `{}` or array `[]`. Primitive roots (a number, a bare string) parse successfully but have nothing to render as a tree. Wrap them in an object if you want the tree explorer.
Converting to CSV loses nested object fields
CSV is flat — nested objects can't be columns. Toggle "Flatten nested objects" to get dot-notation columns like `address.city`, or pre-flatten the JSON with `jq` before conversion.
Frequently Asked Questions
What types of JSON errors can this detect and fix?
The formatter validates all JSON syntax and provides detailed error messages. The 'Fix JSON' feature auto-repairs common issues like trailing commas, single quotes instead of double quotes, and unquoted property names. For other errors, you'll get precise messages to help you debug.
What formats can I convert JSON to?
You can convert JSON to XML (with proper element nesting and escaping), CSV (flattens arrays of objects with header detection), and YAML (with correct indentation and type handling). Each conversion preserves data integrity.
How does the tree view work?
The tree view displays your JSON as an interactive hierarchy. Click nodes to expand/collapse, see type badges (Array[5], Object{3}), and click any node to copy its JSON path. Use 'Expand All' and 'Collapse All' buttons, and the search highlights matching nodes.
Is my JSON data secure?
100% secure. Everything processes locally in your browser — no server requests. Your data is saved in localStorage for convenience between sessions but never transmitted. Safe for API keys, tokens, and sensitive configuration.
Can I upload and download JSON files?
Yes! Click 'Upload' or drag-and-drop a .json file directly onto the input area. After formatting or converting, click 'Download' to save the result as a file.
How do I fix invalid JSON?
The most common causes of invalid JSON are trailing commas, single quotes, unquoted keys, and unescaped characters inside strings. Click 'Fix JSON' to auto-repair these issues, then re-validate. For errors the auto-fixer can't handle (like missing commas or unbalanced braces), the error message tells you the exact line and column to inspect.
What's the difference between JSON and JSONL?
JSON is a single document — one object or array. JSONL (JSON Lines) is a stream of independent JSON objects, one per line. JSONL is common in log files, ML datasets, and streaming APIs because each line can be parsed independently without loading the whole file. To process JSONL in this tool, run one line at a time.
Can I format JSON in VS Code?
Yes — VS Code's built-in formatter handles JSON natively via the Shift+Alt+F shortcut (Windows/Linux) or Shift+Option+F (Mac). The DevPik formatter is more useful when you're already in the browser (e.g., inspecting a network tab payload) or when you need the extra conversions (JSON → XML/CSV/YAML) and auto-fix features that VS Code doesn't include out of the box.
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