How it works
How to use the JSON Viewer
Load your JSON
Paste it, drop a file, or load it from a URL.
Browse the tree
Expand and collapse objects and arrays with the mouse or the arrow keys. Item counts are shown for every container.
Search
Type in the tree search to find matching keys and values; matches are expanded and highlighted automatically.
Copy paths
Select any node to copy its JSONPath (like $.items[0].sku), a JavaScript accessor, or its value.
Keyboard navigation
The tree is fully keyboard accessible. Use ↑/↓ to move, → to expand or step into a node, ← to collapse or go to the parent, Enter to toggle, and * to expand all children. Double-click a node (or press Enter on a value) to jump to it in the input editor.
Built for developers
Why developers use it
Private by design
Everything runs locally in your browser. No uploads, no tracking of your data, no accounts.
Precise errors
Exact line and column, a plain-English explanation and a suggested fix for every syntax error.
Lossless formatting
Big integers, decimals and escapes are preserved byte-for-byte. Only whitespace changes.
Built for large files
A background worker, virtualised rendering and a fast custom parser keep big files smooth.
Tree explorer
Collapsible, searchable tree with JSONPath copying and jump-to-source.
Works offline
Install it as an app or keep using it without a connection once loaded.
FAQ
Frequently asked questions
What is a JSONPath?
JSONPath is a standard way to point to a value inside a JSON document, for example $.store.book[0].title. Many tools (such as jq-like CLIs, API testing tools and databases) accept JSONPath expressions.
Can the viewer handle very large JSON?
Yes. The tree only renders the rows currently on screen, so even documents with hundreds of thousands of nodes scroll smoothly.
Is my JSON sent to a server?
No. Parsing, validation, formatting and the tree view all run in your browser using JavaScript and a Web Worker. Your data never leaves your device. You can even use the tool offline once the page has loaded.
How large a JSON file can I open?
Files of tens of megabytes work well on a modern laptop. Processing runs in a background thread so the page stays responsive, the editor only renders what is visible, and the tree view is virtualised. The hard limit is 200 MB per file.
Does formatting change my numbers?
Never. Many online formatters use JSON.parse, which silently rounds big integers (like 64-bit IDs) and rewrites numbers such as 1.0 or 1e3. This tool keeps every number and string escape exactly as you wrote it — only whitespace changes.
Keep going
Related tools
- JSON FormatterFormat, validate and explore JSON
- JSON ValidatorFind and fix JSON syntax errors
- JSON CompareFind semantic differences between two JSON documents
- JSON DiffSide-by-side or unified line diff of two JSON files
- JSON EditorEdit JSON with live validation
- JSON SorterSort JSON keys alphabetically
- JSON to CSVConvert JSON arrays to CSV and CSV back to JSON
- JSON to XMLConvert JSON to XML and XML to JSON