JSON Viewer

View and explore JSON as a collapsible, colour-coded tree so you can navigate deep structures easily. Runs entirely in your browser.

How to use JSON Viewer: Open JSON Viewer — it runs entirely in your browser with no setup. Paste or type your input into the text area, or upload a file where supported. Set any options you need. The result appears in the output panel — there is no upload step and no waiting on a server. Everything runs inside your browser, so your data never leaves your device.

View and explore JSON as a collapsible, colour-coded tree so you can navigate deep structures easily. Runs entirely in your browser. JSON Viewer is a free, browser-based tool in the Filevane developer tools collection — there is nothing to install, no account to create and no watermark on your results. It works on desktop, tablet and mobile, and because the work happens on your own device it stays fast even with large inputs.

How to use JSON Viewer

Open JSON Viewer — it runs entirely in your browser with no setup.
Paste or type your input into the text area, or upload a file where supported.
Set any options you need. The result appears in the output panel — there is no upload step and no waiting on a server.
Review the output instantly; large inputs are handled locally without lag.
Copy the result to your clipboard or download it. Your data never leaves the page.

Why use JSON Viewer?

100% free with no limits, no sign-up and no watermarks.
Private by design — your data are processed in your browser and never uploaded to a server.
Fast and lightweight, with instant results even on a phone or a slow connection.
Works everywhere — any modern browser on Windows, macOS, Linux, Android or iOS.
Part of a full developer tools suite, so related json viewer tasks are one click away.

What people use JSON Viewer for

Exploring a large API response without scrolling through thousands of lines.
Finding one nested value inside a deeply structured document.
Checking the shape of an unfamiliar payload before writing code against it.

JSON Viewer: limits and things worth knowing

The tree is built by your own browser, which matters here more than for most formatters: API responses routinely contain tokens, customer records and internal identifiers, and pasting one into a server-side viewer discloses all of it.
Collapsed nodes show their child count, so you can judge the size of a branch before expanding it.
Duplicate keys in the source are legal JSON but only the last survives parsing, so a viewer will show fewer keys than the raw text appears to contain.
Very large documents are limited by browser memory rather than by any fixed cap.

Is it private and secure?

Your privacy is built in. JSON Viewer runs completely on your device, so whatever you enter stays in your browser and is never transmitted, logged or stored on any server.

Network activity: none. Nothing is sent and nothing is fetched. This tool makes no network request at all once the page has loaded — which is why it keeps working if your connection drops.

You do not have to take that on trust — our privacy proof page publishes the Content-Security-Policy that enforces it, lists every third party it permits, and shows how to verify the whole claim yourself.

Learn more

Working with JSON, XML and YAML: Format, Validate and Convert — Messy config or API response? Learn to pretty-print, validate and convert between JSON, XML, YAML and CSV in seconds.

See all free developer tools or browse the full tool catalogue.