JSON Tree Viewer Online — Free
Runs 100% in your browser — your files never leave your device.
Deep JSON is hard to scan as plain text, especially when arrays and objects nest several levels. Paste JSON or JSON5 to render a native collapsible tree with type-aware values, optionally sorting object keys recursively while preserving array order.
How it works
- 1
Paste JSON or JSON5
- 2
Expand or collapse tree branches
- 3
Optionally sort object keys
About this tool
What the viewer does
Paste raw JSON and the tool validates, pretty-prints, and renders it as a collapsible tree you can navigate — objects expand, arrays paginate visually, and syntax errors point at their actual location. Everything runs locally; paste payloads with real data freely.
The debugging workflow
API responses arrive minified and single-line; the viewer turns them into navigable structure in one paste. Combined with the syntax locator, it answers both questions at once: is this valid JSON, and if not, exactly where does it break.
Reading large documents
Collapse the branches you do not care about and expand the path you do — the tree turns a 5000-line payload into the three fields you are hunting. For structural comparison between two payloads, the JSON diff shows the differences instead of two trees.
Frequently asked questions
Why does my JSON fail to parse?
The usual suspects: trailing commas, single quotes, unquoted keys, comments — all valid in JavaScript objects, all invalid in JSON. The error position points at the first one.
Does the viewer change my data?
No — pretty-printing adjusts whitespace only. Copy the formatted output and it parses to identical data.
How large a document can it handle?
Megabytes run fine in a modern browser. Extremely deep nesting may hit practical limits — that is a rendering constraint, not a parsing one.