JSON Viewer: Online JSON File & Tree Viewer
Free online JSON viewer for large JSON files. Expand or collapse any node in the tree, search keys and values, and read type badges and child counts.
JSON InputInput
Tree ViewOutput
A JSON viewer renders a JSON file as an expandable outline instead of raw text, so you can read deeply nested data without scrolling through braces. Paste JSON on the left and the right pane shows a collapsible tree with type badges, child counts and key search.
A tree viewer renders JSON as an expandable outline instead of raw text, so structure is something you navigate rather than something you count brackets to find. JSON2X shows each node with a type badge and a child count, collapses branches you are not reading, and searches keys and values across the whole document — all locally, which is what makes it usable on payloads containing credentials.
When is a tree better than formatted text?
Once nesting or size passes the point where indentation stops helping. A formatted 5,000-line document is technically readable and practically not: you cannot see a top-level key and a leaf value at the same time, and scrolling loses your place. Collapsing branches keeps the parts you care about adjacent on screen. Child counts answer questions the text cannot — whether an array holds three elements or three thousand is visible at a glance rather than after a scroll.
How does search differ from Ctrl+F?
Browser find works on rendered text, so it only matches inside branches that happen to be expanded and gives you no structural context. Tree search filters the whole parsed document, including collapsed branches, and keeps each match’s ancestor chain visible so you can see the path that leads to it. On a document with thousands of nodes that difference is decisive: Ctrl+F finds a string, tree search finds where the string lives.
What do the type badges tell you?
They surface the distinctions that cause the most bugs, because JSON’s types are invisible in formatted text until you look closely at the quotes. A badge makes it obvious that "42" is a string and 42 is a number, that null is a value rather than a missing key, and that an empty array and an empty object are different things. Those are exactly the mismatches that break a strongly typed client, and spotting them here is faster than debugging a failed Zod parse later.
How to use the JSON Tree Viewer
Takes under a minute. Nothing is uploaded — every step runs in this browser tab.
- Paste or open your JSON
Put the document into the left-hand input pane. Large files are parsed off the main thread so the tab stays responsive.
- Expand what you need
The right-hand pane shows the tree collapsed to the top level. Click a node to expand it, or expand and collapse everything at once.
- Search for a key or value
Filter the tree to matching nodes, with their ancestors kept visible so you can see where each match sits.
- Copy a subtree or its path
Copy any node’s value as JSON, or copy its path to reuse in code or in a JSONPath expression.
When to use it
- Understanding the shape of an unfamiliar API response before writing code against it
- Finding one field inside a large, deeply nested configuration file
- Checking how many elements an array actually contains
- Reading a JSON log entry or webhook body that arrived as a single line
- Explaining a payload’s structure to someone during a review or a debugging session
Step-by-step guides for this tool
Task-specific walkthroughs covering the most common ways this tool gets used.
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Frequently Asked Questions
How does the JSON Tree Viewer work?
It renders your JSON document as an interactive DOM tree with expandable/collapsible nodes, node type badges, node item counts, and live key/value search.
How do I open and read a JSON file online?
Open the file in any editor, copy its contents, and paste them into the left pane — the tree renders immediately. Expand only the branch you need; type badges and child counts often answer the question without expanding at all.
Can it handle large JSON files?
Yes. Hit Collapse all to reduce a huge document to its top-level keys, then expand only the branch you need; the header also reports total key count and nesting depth. Size is bounded by your device memory rather than a server quota.
Is this JSON viewer free, and is my file uploaded?
It is free with no account, and nothing is uploaded. Parsing and rendering happen in your browser, which is what makes it usable on production exports and customer data.
How do I search for a key or value in the tree?
Type in the search box and rows that do not match are dimmed, so matching keys and values stay visible in their original position instead of being pulled out of context.
Related Developer Tools
- Standards & references:
- JSON
Last reviewed by the JSON2X Engineering Team.