Utilities

JSON Editor

Edit, format, and validate JSON with syntax highlighting and real-time error detection — powered by Ace Editor, fully in-browser.

JSON Editor0 chars

About This Editor

Powered by Ace Editor — a mature, battle-tested code editor used in Cloud9 and countless developer tools. Supports syntax highlighting, code folding, and auto-completion for JSON. For quick format/minify, try the JSON Formatter.

Keyboard Shortcuts

Ctrl/⌘ + Z — Undo
Ctrl/⌘ + Y — Redo
Ctrl/⌘ + F — Find
Ctrl/⌘ + H — Find & Replace
Ctrl/⌘ + A — Select all

Common JSON Mistakes

Trailing commas after last item
Single-quoted strings (use double quotes)
Unquoted keys
Comments (not allowed in standard JSON)
undefined values — use null

Frequently Asked Questions

Is my JSON data sent anywhere?

No — the editor runs entirely in your browser. No data is transmitted or stored on any server.

What is the difference between Format and Minify?

Format adds 2-space indentation and newlines for readability. Minify removes all whitespace to reduce payload size. Both operations preserve the exact same data.

Can I edit large JSON files?

Yes — Ace Editor handles large files efficiently with virtual rendering. For multi-MB files, folding nested sections keeps navigation manageable.

Can JSON have comments?

Standard JSON (RFC 8259) does not allow comments. Use JSONC or JSON5 for config files that need comments — VS Code and many tools support these variants.