JSON Tree Viewer

Paste JSON to explore it as a collapsible tree instead of scrolling through raw text. Great for large API responses or deeply nested config files.

JSON Input — drag a file in, or

How to use it

Paste valid JSON, drop a local file onto the input, or choose Load Example.
Select View Tree or press Ctrl/⌘ + Enter.
Open or close individual objects and arrays by selecting their summaries.
Use Expand All and Collapse All when you need a complete overview or a compact top-level outline.

JSON tree example

Consider an API response with a nested user and an array of roles:

{
  "user": {
    "id": 42,
    "profile": {"name": "Ada", "active": true},
    "roles": ["admin", "editor"]
  }
}

The root object appears as one expandable branch. Opening user reveals id, profile, and roles; opening the array displays indexed values such as [0] and [1]. Strings, numbers, booleans, and null values use different colors so types are easier to scan.

Why use a tree instead of formatted JSON?

Pretty-printed JSON is ideal when you need to edit or copy a document, but deeply nested data can still become a long wall of text. A collapsible tree lets you hide branches that are not relevant and follow one part of the structure at a time. This is useful when an API response contains large metadata blocks, repeated items, or optional objects several levels deep.

The tree preserves array order and object keys exactly as parsed. It does not sort keys, filter values, or change the source document. If you need to extract a particular path rather than browse manually, use the JSONPath Tester.

Common uses

Inspect nested REST or GraphQL responses during debugging.
Explore configuration files before changing a specific setting.
Review webhook payloads with optional and repeated sections.
Understand unfamiliar fixtures, logs, or exported application data.
Locate the path of a value before writing a JSONPath expression.

Invalid JSON and performance

The viewer requires strict JSON. Missing commas, trailing commas, comments, and single-quoted strings are reported with a line and column instead of producing a partial tree. Use JSON Validator to inspect syntax or JSON Repair for common JavaScript, JSONC, and Python-style differences.

The browser parses and renders the complete document before it can display the tree. Collapsing branches reduces visual clutter but does not remove those nodes from memory. Documents with many thousands of values may take longer to render, and very large files can make the tab unresponsive. Keep an original copy and start with collapsed sections when reviewing a large payload. All parsing and rendering stays inside the current browser tab.

Frequently Asked Questions

Does this work for very large JSON files?

The browser parses and renders the full tree locally. Documents with many thousands of nodes can work, but very large or deeply nested files may slow the tab even when branches are collapsed.

Can I copy a single value from the tree?

Select the text of any leaf value directly — the tree is built from real text, not an image or canvas, so browser text selection and copy work normally.

Is the JSON uploaded to Cryonel?

No. File reading, parsing, and tree rendering happen in the current browser tab. Cryonel does not receive the JSON you paste or open.