JSON Viewer
Paste JSON and explore it as a collapsible, colour-coded tree — great for large API responses.
Your JSON is parsed entirely in your browser — nothing is uploaded.
Frequently Asked Questions
What JSON does it accept?
Strict standard JSON — double-quoted keys and strings, no trailing commas, no comments. Anything the browser's JSON parser rejects will be flagged with an error.
How is this different from a JSON formatter?
A formatter re-indents the text; the viewer renders a collapsible tree you can fold and unfold to explore large structures. They complement each other.
Is my data sent to a server?
No. This tool runs entirely in your browser using JavaScript — nothing you enter is uploaded or stored.
The JSON Viewer parses JSON and renders it as a colour-coded, collapsible tree, so you can explore a large or deeply-nested structure without scrolling through a wall of text. It complements a formatter: where a formatter re-indents text, the viewer lets you fold and unfold objects and arrays to focus on the part you care about.
How to Use This Tool
Paste your JSON and press View Tree. Click any object or array node to collapse or expand it, or use Expand all / Collapse all. Invalid JSON is reported with the parser's error message so you can fix it.
What This Tool Checks
Strict, standard JSON via the browser's native parser — double-quoted keys and strings, no trailing commas, no comments. Keys, strings, numbers, booleans and null are colour-coded by type.
Understanding Your Results
A rendered tree means the JSON is valid. Collapsed nodes show a count of their children so you can gauge size at a glance. If parsing fails, the error points to where the parser first got confused — the real mistake is usually there or just before it.
How to Fix Common Problems
The usual culprits are trailing commas, single quotes instead of double quotes, unquoted keys, and JavaScript-style comments. Fix those and the tree will render. For very large payloads, collapse the top level first, then drill into one branch at a time.
SEO Best Practices
Use the viewer to understand the shape of an unfamiliar API response before writing code against it. Because everything runs in your browser, it is safe to paste sensitive responses here — but be careful with viewers you do not control.
Example
Pasting a nested API response of users, each with an array of orders, lets you collapse the users you are not interested in and expand just the one order you are debugging — far faster than reading the raw text.
Common Mistakes to Avoid
Expecting it to accept JSON5 or JavaScript object literals — it is strict JSON only. Pasting confidential data into an online viewer you do not trust (this one is browser-only, but many are not).
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