JSON Editor

How do I edit JSON online?

Edit JSON online with syntax colouring, errors marked as you type, bracket matching and one-click formatting. Free and private: nothing leaves your browser.

Type or paste JSON, or open a file of up to 1 MB. Keys, strings, numbers and punctuation are coloured as you type, and a moment after you stop, the document is checked: the first error is underlined where it is, marked beside its line number and described in words, with its line and column. Warnings, such as a key used twice or a number too large for JavaScript to hold exactly, are listed below.

Which keys does the editor use?

Enter keeps the line's indent, and indents one step more after { or [. Tab and Shift+Tab indent and outdent the selected lines; press Esc then Tab to move on from the editor, or tick Tab key moves focus. Next to a bracket, it and its partner are marked, and Ctrl+M (⌘M on a Mac) jumps between them. Format, Minify and Sort keys rewrite the whole document, and Ctrl+Z (⌘Z) undoes them like any other change.

Are my numbers kept exactly?

Yes. Formatting and sorting keep every number exactly as written, so 12345678901234567890 and 1.10 stay as they are, unlike tools that read numbers into JavaScript first.

Is my JSON saved or sent anywhere?

No. It stays in this page and is never stored, even with Remember settings ticked, which keeps only the layout and Tab setting. Because there is no other copy, the page asks before you leave with unsaved changes. Download saves your work as a file.

What is coming next?

A tree view for editing values, renaming keys and moving items without touching the text, then JSON Schema validation and JSONPath filters. For reading very large files, use the JSON Formatter.