An online JSON editor with a live check on every change
This online JSON editor gives you a proper code editor for JSON files together with a parser that watches what you type. Change a value, add a key or paste in a new block, and a moment later the tree on the right shows the updated structure, or the status bar tells you exactly what broke.
It is meant for the everyday edits that do not justify opening an IDE: adjusting a config file, fixing a fixture for a test, trimming an API response before sharing it, or cleaning up JSON someone pasted into a chat.
What the editor can do
- Syntax highlighting for keys, strings, numbers and literals, with a dark theme when the site is in dark mode.
- Line numbers and folding. Arrows in the gutter collapse an object or array so you can move a large block out of the way while you work on another.
- Bracket help. Matching brackets are highlighted, and typing an opening quote or bracket inserts the closing one.
- Search and replace with Ctrl+F (Cmd+F on a Mac), which is handy for renaming a key that appears many times.
- Tab to indent selected lines, plus the usual undo and redo history.
Example: catching a missing comma
Suppose you add an autosave setting to this file but forget the comma on the line before:
{
"theme": "dark",
"fontSize": 14
"autosave": true
}The status bar shows Invalid JSON: Expected ',' or '}' but found '"' (line 4, column 3), and the same message appears under the editor with a Go to error button that puts the cursor on line 4. Notice that the report points at the start of the new key, not the end of line 3: the parser only realizes something is missing when it reaches the next token. When an error seems to be on a correct line, look at the line above it.
The tree is for checking, the text is for editing
The tree view is read-only. It exists to confirm that your edit produced the structure you intended, for example that a new object landed inside settings and not beside it. All changes happen in the text editor on the left. After a structural edit, glance at the item and key counts in the tree and at the depth in the status bar; a sudden change in depth usually means a bracket ended up in the wrong place.
Tidying up before you save
Hand edits tend to leave indentation uneven. Format rewrites the whole document with a 2-space indent, and Sort keys puts object keys in alphabetical order, which makes the next diff smaller if your team keeps files sorted. Minify writes the edited document on a single line when it needs to go into an environment variable or a request body.
If you pasted something that is not quite JSON, such as a JavaScript object with unquoted keys and single quotes, Repair converts it to valid JSON so you can keep editing.
Keeping and sharing your work
Download saves the editor text as json-editor.json. Save & Share stores the text and copies a link to your clipboard; opening that link later loads the saved JSON back into the editor. If you are signed in, you can choose whether a saved link is unlisted, public or private.
To see what changed between the original file and your edited copy, paste both into the JSON diff tool. To strip nulls and empty values in bulk instead of deleting them one at a time, use the JSON cleaner. For quick reading without editing, the JSON viewer keeps the focus on the tree.
Privacy
Editing, validation and formatting all run inside your browser tab, and nothing you type is uploaded while you work. Content reaches our server only when you choose Save & Share.