JSON Designer

JSON

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JSON Designer runs on your device

Runs in your browser

No uploads.There is no file-upload endpoint on duck.tools. This tool process your input inside this browser tab.
No tracking.No analytics and no tracking cookies. Sign-in uses a session cookie and loads Cloudflare Turnstile only when you open the account dialog.
We never see your data.Your file never reaches a Duck Tools server, so there is nothing for us to store, read or leak.

The document is built and previewed in this page. Nothing is sent to Duck Tools or anywhere else.

To be precise: your browser still downloads this page, its scriptsover the network, and our web server keeps standard access logs. What never travels is the content you put into a local tool.

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JSON Designer

Build JSON structures and datasets from a visual editor, then copy the result.

Add objects, arrays, strings and numbers with a simple nested editor. Load existing JSON, grow a dataset row by row, and copy or download the document. Everything stays in this tab.

How it works

Start from a blank object or load a sample / existing JSON file.
Add fields, pick a type, and nest objects or arrays as needed.
Edit keys and values in place. Duplicate a row to grow a dataset.
Copy or download the generated JSON from the preview.

Also known as

json
designer
editor
dataset
builder
structure

Related tools

JSON FormatterPretty-print JSON and inspect it as text or a collapsible tree.
JSON ValidatorCheck JSON syntax and see the line, column and a short hint.
JSON ConverterConvert JSON to YAML, XML, CSV, TSV, NDJSON or dotted keys.

LOCALRuns in your browser

No uploads.There is no file-upload endpoint on duck.tools. This tool process your input inside this browser tab.
No tracking.No analytics and no tracking cookies. Sign-in uses a session cookie and loads Cloudflare Turnstile only when you open the account dialog.
We never see your data.Your file never reaches a Duck Tools server, so there is nothing for us to store, read or leak.

The document is built and previewed in this page. Nothing is sent to Duck Tools or anywhere else.

To be precise: your browser still downloads this page, its scriptsover the network, and our web server keeps standard access logs. What never travels is the content you put into a local tool.

More json tools →Full privacy page →