JSON Builder

Build nested JSON visually — and keep code perfectly in sync.

Left: drag, reorder, and collapse sections. Right: paste JSON, auto-format, and get clean syntax highlighting.

Visual structure
Drag the handle to reorder. Expand objects/arrays to edit nested fields.
object
{ … }
string
string
array
[ … ]
string
#0
string
#1
string
#2
Drag items here to reorder within this container.
boolean
Drag items here to reorder within this container.
object
{ … }
string
number
Drag items here to reorder within this container.
Root
Add top-level fields and drag to reorder. Expand containers to edit nested data.
JSON
Paste/modify JSON here. Valid JSON instantly updates the left side.
Valid