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JSON Studio
Pretty-print, minify, or explore JSON as an interactive tree — copy and download. All processed locally.
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Output initialises when this pane is visible.
Turn messy or minified JSON into readable, consistently indented text.
A JSON formatter (also called a pretty-printer) takes compact or poorly spaced JSON and rewrites it with consistent indentation and line breaks so humans can read and edit it. Minified JSON from APIs is valid but hard to scan; formatting reveals structure, nesting depth, and duplicate keys at a glance.
This formatter also offers an interactive tree view to browse objects and arrays, plus a minify mode to collapse whitespace when you need a compact payload for logs or production. When JSON fails to parse, an Auto-fix button in the status bar attempts safe repairs — trailing commas, unquoted keys, comments, and more. All processing happens locally in your browser — paste confidential data without worry.
Use it when debugging API responses, reviewing config files, or preparing JSON before a diff or schema check. For deeper validation workflows, see our JSON Schema validation guide.
Format, minify, or browse JSON as a tree — all processed locally in your browser.
When JSON fails to parse, an Auto-fix button appears in the status bar. It can fix trailing commas, unquoted keys, comments, single-quoted strings, unclosed brackets, and JS-style wrappers like const data = ….
Review the result before exporting — complex errors may still need manual editing.
Tree shows a collapsible hierarchy — click nodes to jump to the matching key in the input. Format pretty-prints with 2-space indentation; toggle Minify in the output toolbar for a compact line.
Ctrl/⌘ + T tree · Ctrl/⌘ + S format · Ctrl/⌘ + Shift + M minify
Import a .json file, paste from the clipboard, or use From URL when CORS allows.
Need diff, schema validation, or converters? Open JSON Editor Pro for the full workspace.
What this formatter offers — tree view, pretty-print, and minify.
Browse JSON as a collapsible tree with breadcrumbs, expand/collapse, and search.
Format JSON with readable 2-space indentation as you type.
Collapse whitespace into a compact single-line payload for production.
One-click repair for trailing commas, comments, unquoted keys, and other common paste mistakes — appears in the status bar when JSON fails to parse.
Push output back to the input pane, or copy and download instantly.
All processing runs in your browser. Nothing is uploaded.
Common questions about the JSON formatter.
Yes, completely. All processing — parsing, formatting, diffing, schema validation, and transformation —
happens entirely inside your browser. Your data is never sent to any server, never stored in the cloud,
and never shared. The only persistence is your own browser's localStorage, which you can
clear at any time.
Yes. Once the page has been loaded and the editor assets are cached, all features work without a network connection. The Monaco editor, AJV validator, and all transform logic run locally. The only time the network is used is to load CDN assets on the very first visit, and optionally when using "Load from URL".
Auto-fix handles many common non-standard JSON issues: trailing and missing commas, duplicate commas,
single-quoted strings, unquoted keys, // and block comments, JavaScript literals like
undefined, unclosed { / [ brackets, and text wrapped in assignments
such as const config = …. It runs entirely in your browser. If repair fails, the error
message in the status bar still points to the line that needs manual attention.
The editor handles files up to several megabytes comfortably. Above 1 MB, some features like code folding are automatically disabled to keep the editor responsive. For very large files (10 MB+) you may notice slower tree rendering, but formatting, diff, and transform continue to work.
Draft-07 (default), Draft 2019-09, and Draft 2020-12 — all via AJV. The dialect is auto-detected from the
$schema field in your schema document, but you can override it with the dialect chip in the
Schema pane. An "Infer from input" button generates a starter schema from your current JSON automatically.
TOON (Token-Oriented Object Notation) is an experimental
data serialization format designed to be more compact, token-efficient,
and easier for AI systems and humans to process compared to traditional
formats like JSON.
Traditional formats such as JSON contain a lot of structural punctuation
like braces, commas, and quotation marks. TOON-style formats attempt to
reduce this syntactic overhead while preserving structured data.
Large Language Models (LLMs) process text as tokens. JSON can become
verbose because of repeated punctuation and quoted keys. TOON-style
formats aim to reduce token usage, making prompts and structured data
more compact for AI workflows.
Reduces unnecessary syntax to save prompt space and improve AI
context efficiency.
Minimizes clutter from braces, commas, and quotation marks.
Some implementations aim for deterministic parsing and lightweight
streaming support.
Optimized for agent memory, prompt engineering, and structured AI
communication.
TOON is not currently a universally standardized format. Different
implementations may use different syntax rules and parsing strategies.
When working with TOON, it is important to define or reference the
specific grammar being used.
TOON (Token-Oriented Object Notation)
Core Idea
JSON Example
{
"name": "John",
"age": 25,
"skills": ["JS", "Python"]
}
TOON-style Example
name: John
age: 25
skills[
JS
Python
]Why “Token-Oriented”?
Main Goals
Lower Token Usage
Better Readability
Faster Parsing
AI-Friendly Structure
TOON vs JSON
Feature
JSON
TOON-style
Standardized
Yes
Usually Experimental
Verbosity
Higher
Lower
LLM Efficiency
Moderate
High
Browser Support
Native
Limited
Human Readability
Good
Often Better
Ecosystem
Massive
Small / Emerging
Important Note
Related Formats
Potential Use Cases
Yes. Switch to Diff mode (Ctrl/⌘+D) and use the Sort button on each side. Sorting recursively normalises both object-key order and array element order before comparing, so two semantically identical JSONs with shuffled keys will show zero differences.