JSON Editor
Write and correct JSON in a real code editor instead of a plain text box, with mistakes flagged as you type.
Your data stays on your device
JSON document
- characters
- 0
- lines
- 0
- size
- 0 B
About this tool
Editing JSON in a textarea is error-prone: there is nothing to match brackets, nothing to colour strings differently from keys, and no feedback until you paste the result somewhere that rejects it. This page gives you a proper editing surface.
Validation runs on a short debounce while you type, so the error indicator reflects the current state of the document without re-parsing on every keystroke. Formatting and minifying operate on the buffer in place, keeping your cursor context.
How to use this tool
- Paste, upload or start typing JSON in the editor.
- Watch the status bar: it shows valid, or the line and column of the first problem.
- Use Format to re-indent the document, or Minify to compact it, without leaving the editor.
- Copy the buffer or download it as a .json file when you are done.
Key features
- Line numbers and a gutter that marks the failing line
- Syntax highlighting for keys, strings, numbers, booleans and null
- Bracket matching and automatic indentation on new lines
- Live validation with a debounce so typing stays smooth
- Format and minify applied directly to the editor buffer
- Configurable tab size and a full-screen editing mode
Example
Input — JSON
{
"name": "svc"
"port": 8080
}Output — JSON
Line 3, column 3 — expected "," or "}" before this key.Good to know
- The document is held in memory only. Refreshing the page discards unsaved work, because nothing is stored on a server.
- There is no schema-aware autocomplete; suggestions would require knowing your data model.
- If the editor component fails to load, the page falls back to a plain textarea. Editing still works, but highlighting and the gutter are unavailable.
Frequently asked questions
Is my document saved between visits?
No. Nothing is written to a server and nothing is persisted by default, so closing the tab clears the buffer. Download the file if you need to keep it.
What keyboard shortcuts are available?
Ctrl or Cmd + Enter runs the primary action, Ctrl or Cmd + Shift + C copies the result, and Ctrl or Cmd + F opens the editor search panel.
Why does the error marker lag slightly behind my typing?
Validation is debounced by a few hundred milliseconds. Parsing on every keystroke would make large documents feel sluggish for no practical benefit.
Can I edit JSON with comments?
The editor will let you type them, but validation will flag them, because comments are not part of the JSON specification.
Your data stays on your device
Your data is processed locally in your browser and is not uploaded to our server. This page keeps working after you go offline, because there is nothing to send.