Are my files uploaded?

No. Files are opened and processed by your browser on this device. Nothing is sent to a server, so it works with private documents and even offline once the page has loaded.

How big a file can it handle?

Tens of megabytes in a modern browser. The tree view shows the first 2,000 items of each list.

Nightroll

Free JSON Formatter & Validator

Paste JSON to check it, format it or explore it as a tree.

Indent

How to make formatted JSON

Paste JSON or open a file.
See at once whether it is valid, and where the error is if not.
Format, minify or sort keys, then copy or download.

Frequently asked questions

Are my files uploaded?: No. Files are opened and processed by your browser on this device. Nothing is sent to a server, so it works with private documents and even offline once the page has loaded.
How big a file can it handle?: Tens of megabytes in a modern browser. The tree view shows the first 2,000 items of each list.