JSON Viewer
Explore, format and validate JSON in a collapsible tree.
About JSON Viewer
Open a JSON file to browse it as a collapsible, searchable tree, pretty-print or minify it, see exactly where a parse error is, and copy or download the formatted result.
Minified JSON is unreadable by design, and the usual fix — pasting it into an online formatter — means pasting whatever it contains into somebody else’s server.
Browse it as a collapsible tree, pretty-print it, or minify it.
- Processed on your deviceEverything you open or type here is handled by this page and never uploaded anywhere.
- No queue, no limitsNothing waits on a server, so the only limit is your own hardware.
- No account neededNo sign-up and no email address required.
How JSON Viewer works in your browser
Parsing uses the browser’s own JSON implementation. The same engine your application uses reads the text, which means anything accepted here your code will accept too, and the output of formatting is guaranteed valid.
That also means the parser is strict, as the specification requires. Trailing commas, single-quoted strings, comments and unquoted keys are rejected rather than quietly repaired — and when parsing fails, the position of the first token that could not be accepted is reported so you can find it.
Key order is preserved exactly as written, so a formatted document still diffs cleanly against the original in version control.
When to use it
Reading a minified API response pulled out of a browser’s network tab. Finding the exact position of a syntax error a build tool only called "invalid". Exploring a deeply nested configuration file without scrolling through one long line. Inspecting a payload containing credentials or customer data, which should not be pasted into a third-party formatter.
Frequently asked questions
What happens if my JSON is invalid?
You get the exact line and column where parsing failed, plus the character that caused it — far more useful than a generic error when hunting a missing comma.
Can I copy just one part of a large document?
Not directly. The copy button takes the whole formatted or raw document. To lift one nested object, collapse the tree to find it, then copy the document and cut that part out.
Does it support JSON Lines and GeoJSON?
GeoJSON, yes: it is ordinary JSON and gets the same tree view. A JSON Lines file is not one JSON document, so it is reported as invalid and shown as raw text with the position of the first error.