JSON viewer and tree browser
Text is a poor way to understand an unfamiliar payload. The tree view shows structure first: expand what interests you, collapse what does not, and read the path of anything you land on.
Open the tree →Built for documents that are too big to read
Rows are virtualised, so only what is on screen is rendered and a document with tens of thousands of nodes scrolls smoothly. Expand-all is budgeted rather than optimistic: it expands as much as it can — up to 15,000 containers — and tells you what it did instead of freezing while it tries to open everything.
Every node knows where it is
Each row shows its key, a type-coloured value, and for containers the number of children. Selecting a row puts its full JSON path in the status bar, one click from your clipboard, and you can jump from a tree node straight to the matching line in the editor. Hovering a value in the editor works the other way round, showing the path without leaving the text.
Editing without reformatting the file
Values can be edited, keys added and nodes deleted directly in the tree, and the edit is applied to the document text rather than to a parsed copy — so the formatting of every line you did not touch is preserved, along with the exact text of numbers. Adding a value shows you how it will be stored (as a string, a number, a boolean or null) before you commit it.
Questions
Can it open large JSON files?
Yes. The tree is virtualised so rendering cost does not grow with document size, and analysis runs off the main thread. Multi-megabyte documents are usable; expand-all is capped at 15,000 containers and reports when it stops.
Can I edit values in the tree?
Yes — edit a value, add a key or delete a node. Changes are written into the document text, leaving untouched lines formatted exactly as they were.
How do I get the path to a nested field?
Select the row: its full path appears in the status bar and can be copied in one click. Hovering the value in the editor shows the same path.
Does viewing a file upload it?
No. Files you open stay in your browser; the app has no backend.