Free Online JSON Viewer & Formatter — Paste JSON, See It Render

JSON
Tree
✓ valid · 25 nodes · depth 3
"tool": "json-viewer",
"version": 1,
"free": true,
"paste",
"format",
"tree"
],
"uploads": 0,
"signup_required": false,
"max_size_mb": 5
},
]
}
more tools

Other tools in the toolbox.

All live, all free, all browser-only. No signup, no limits.

See all →
01
Live
HTML Viewer
Paste HTML from Claude, ChatGPT, or your editor — see it render live. Device frames, share links, zero setup.
Open →
02
Live
Markdown Editor
Write markdown, see clean semantic HTML render next to it. Light and dark preview. Copy the HTML out in one click.
Open →
03
Live
HTML → PDF
Render HTML to a print-perfect PDF in one click. Respects @page rules, headers, footers, page breaks.
Open →
04
Currently using
JSON Viewer
Paste minified, deep, or messy JSON — read it as a collapsible tree. Format, minify, copy. Browser-only.
↻ on this page
frequently asked

JSON viewer
questions, answered.

Full FAQ →
Paste minified or messy JSON and read it as a collapsible tree. The left pane is a CodeMirror editor with JSON syntax highlighting and undo. The right pane shows the parsed structure — type-tinted leaves, expand/collapse on every branch, and a status line above the tree confirming valid JSON or pointing at the parse error.
Yes. Click Format to reflow the source into 2-space indentation, Min to grab a single-line minified blob, or Copy to grab the pretty version. All three operate on the parsed object, so they double as a quick is-this-even-valid-JSON check.
The status line above the tree shows × with the parser's error message and the exact line and column. The tree pane shows a friendly error card with the same info. Fix the source on the left and the right side updates as you type.
No. Parsing, formatting, and rendering happen entirely in your browser. There is no backend that sees your JSON. Your last draft is saved to localStorage on your own device so closing the tab doesn't lose your work.
about

A free online JSON viewer.
Paste, read, copy.

The JSON viewer is a free online JSON viewer and formatter that turns minified, messy, or deeply nested JSON into a collapsible tree you can actually read. Type-tinted leaf values, expand/collapse on every branch, exact line/column reporting on parse errors, and a Format action that reflows the source into 2-space indentation.

Use it for debugging a noisy API response when the network tab's pretty-printer falls short, reading a log dump where every event is one minified line, inspecting a deeply nestedtsconfig or webpack config, or comparing two JSON payloads side-by-side by formatting both first.

Paste, format, copy. The CodeMirror editor on the left has JSON syntax highlighting and undo. The right pane shows either the parsed tree (when valid) or the parse-error message with the exact line and column (when not). Copy grabs the pretty-printed version, Min grabs a single-line minified blob — both run on the parsed object, so they double as a quick "is this even valid JSON?" check.

Nothing is sent to a server. There's no jq, no JSONPath query language, no schema validation — the goal is reading and reformatting, not transforming. If you need to render structured prose as readable HTML instead, the Markdown editor is the parallel tool. Why these tools. Full FAQ.