A code editor for JSON, right in your browser
JSON Editor
Open a .json file or paste JSON and edit it with syntax highlighting, live error checking, code folding and search and replace. Browse the structure in the tree view, then download or copy your changes. Nothing is uploaded.
Tip: Ctrl + Enter runs Format Changes
Valid JSON
230 B13 linesdepth 2Processed in your browser
An online JSON editor that works like your IDE
This JSON editor uses Monaco, the same editor engine that powers Visual Studio Code. You get syntax highlighting, bracket matching, code folding, multi-cursor editing, find and replace and undo history, without installing anything.
As you edit, the document is validated continuously, and errors are underlined in the editor and explained below it. Formatting only happens when you ask for it, so typing never rearranges your text. The tree view beside the editor shows the structure of your JSON, with item and property counts, so you can check what you changed.
How to edit a JSON file online
- 1
Open your file
Press Open file or drag a .json file onto the editor. You can also paste JSON or start typing.
- 2
Make your changes
Edit values, add properties or remove items. Use Ctrl + F to find and Ctrl + H to replace across the document.
- 3
Check the result
Watch the status for errors and use the tree view to confirm the structure. Press Format Changes to tidy indentation.
- 4
Save
Press Download to save the file with its original name, or Copy to paste it elsewhere.
Keyboard shortcuts
The editor supports the shortcuts you know from VS Code. On macOS, use Cmd instead of Ctrl.
| Shortcut | Action |
|---|---|
| Ctrl + Enter | Run the main action (Format Changes) |
| Ctrl + F / Ctrl + H | Find / find and replace |
| Ctrl + Z / Ctrl + Shift + Z | Undo / redo |
| Alt + Up / Down | Move the current line |
| Ctrl + D | Select the next match for multi-cursor editing |
| Ctrl + Shift + [ / ] | Fold / unfold the current block |
What people edit with it
- Config files
- Change ports, hosts and feature flags in appsettings.json, firebase.json or a Terraform variables file.
- Test fixtures and mocks
- Adjust sample payloads for unit tests, Storybook stories or mock servers.
- API request bodies
- Draft or tweak a POST body before pasting it into Postman, Insomnia or curl.
- Translation files
- Update i18n JSON files such as en.json without a full development setup.
Keep the right types when editing
A common editing mistake is quoting a value that should be a number or boolean. Applications often treat "true" and true differently.
| Type | Example | Note |
|---|---|---|
| String | "staging" | Always double quotes |
| Number | 8080 | No quotes, no leading zeros |
| Boolean | true | Lowercase, no quotes |
| Null | null | Lowercase, no quotes |
| Array | ["a", "b"] | Ordered list |
| Object | {"key": "value"} | Unordered key/value pairs |
Saving your work
Edits live in this browser tab only. They are not saved to an account or a server, so press Download or Copy before you close or refresh the page.
JSON Editor FAQ
How do I open a JSON file online?
Press Open file and pick the file, or drag it onto the editor. It opens instantly because it is read by your browser, not uploaded.
Are my edits saved?
No. Nothing is stored between visits. Download or copy your JSON before leaving the page.
Does the editor reformat my JSON as I type?
No. Your text stays exactly as you type it. Press Format Changes or Ctrl + Enter when you want consistent indentation.
Can I find and replace in JSON?
Yes. Press Ctrl + F to find or Ctrl + H to find and replace (Cmd on macOS). Regular expressions and case matching are supported.
Is there a tree view?
Yes. The tree view beside the editor shows objects and arrays as collapsible branches with counts. It updates as you edit, whenever the JSON is valid.
Can I edit very large JSON files?
Yes, within your device's memory. The editor only renders visible lines, so files of several megabytes stay smooth. Files over 60 MB are refused.