ilovejson
Blog
JSON
Font size
Save

Paste, drop a file, or fetch a URL to get started.

JSON · JSON5 · JSONL · Python · Ruby · PHP

Ln 1, Col 1 1 line Ctrl+Enter to parse · Ctrl+Shift+F to format © 2026 ilovejson

What is ilovejson?

ilovejson is a free, fast, and fully private online JSON tool built for developers. It runs entirely in your browser — no data is ever uploaded to any server, making it safe for production API responses, confidential configs, and sensitive data.

Unlike most JSON formatters that stop at the first syntax error, ilovejson shows all errors at once with red wavy underlines, exact line and column numbers, and one-click Fix All — just like VS Code.

How to Format JSON Online

  1. Paste your JSON, minified JSON, or broken JSON into the input pane on the left.
  2. The tool auto-parses and shows the tree view on the right instantly.
  3. Click Format (or press Ctrl+Shift+F) to pretty-print the JSON back into the editor.
  4. Switch to Text view to see the formatted output. Use Wrap, Unwrap, or Minify to control the output style.
  5. Copy or download your formatted JSON.

Common JSON Errors and How to Fix Them

Missing comma
Every property in a JSON object must be separated by a comma. ilovejson highlights the exact value missing the comma and offers a Fix All button to insert all missing commas at once.
Trailing comma
Standard JSON does not allow a comma after the last item in an object or array. JSON5 does allow this — paste your JSON5 into ilovejson and it will be converted automatically.
Unquoted keys
JSON requires all object keys to be double-quoted strings. JavaScript object literals and Python dicts often have unquoted keys — ilovejson detects and fixes these automatically.
Single-quoted strings
JSON only allows double quotes. Single-quoted strings (common in Python and JavaScript) are detected and converted automatically.
Bad control character
Invisible control characters (like tabs or newlines inside string values) cause JSON parse failures. These are highlighted and can be found using the search feature.

Frequently Asked Questions

Is my JSON data private?

Yes, completely. ilovejson runs 100% in your browser using JavaScript. No data is sent to any server, logged, or stored anywhere outside your own browser. You can even use it offline after the first load.

What formats does ilovejson support?

Standard JSON, JSON5 (with // comments and trailing commas), JSONL/ndjson (JSON Lines), Python dicts (None/True/False), Ruby Hashes (symbol => syntax), PHP arrays, and JavaScript object literals with unquoted keys — all auto-detected.

How do I compare two JSON files?

Click the Diff button in the top bar. The editor switches to a side-by-side view — paste your original JSON on the left and modified JSON on the right. Added lines are highlighted green, removed lines red, and changed lines yellow.

What is JSONL (JSON Lines)?

JSONL (also called ndjson or newline-delimited JSON) is a format where each line is a valid JSON object. It is commonly used for log files, data pipelines, and streaming APIs. ilovejson parses each line separately and shows them as individual collapsible records in the tree view.

Can ilovejson handle large JSON files?

Yes. The tree view uses virtual scroll — only the rows visible on screen are rendered as DOM nodes, regardless of file size. Files up to 500MB have been tested without performance issues.

What is JSON5?

JSON5 is a superset of JSON that allows JavaScript-style comments (// and /* */), trailing commas, unquoted keys, and single-quoted strings. It is often used in configuration files (like VS Code's settings.json). ilovejson converts JSON5 to standard JSON automatically.

How do I load JSON from a URL?

Click Open URL in the top bar and paste any URL that returns JSON. Alternatively, add ?url=https://api.example.com/data to the ilovejson URL to load it directly on page open — useful for sharing pre-loaded views.