JSON Formatter - Beautify, Minify & Validate
Free online JSON formatter. Beautify, minify, validate, and explore JSON with Tree View. No signup needed.
About This Tool
JSON Formatter is a developer tool that validates, formats, and minifies JSON data instantly in your browser. It supports tree-view visualization, customizable indentation (2/4 spaces or tabs), and syntax highlighting. Ideal for API developers, backend engineers, and anyone working with JSON configuration files.
How It Works
JSON (JavaScript Object Notation) is a lightweight data-interchange format defined by RFC 8259. When you paste raw JSON into this tool, it first runs a full parse using a recursive-descent parser that builds an Abstract Syntax Tree (AST). If the input contains syntax errors — such as trailing commas, unquoted keys, or mismatched brackets — the parser pinpoints the exact line and column of the error.
Once the AST is validated, the formatter re-serializes it with the indentation level you choose. The "beautify" mode inserts newlines and spaces at each nesting level for human readability. The "minify" mode strips all unnecessary whitespace, producing the smallest possible output for network transfer. The tree-view mode renders the AST as a collapsible hierarchical structure, letting you expand and collapse nested objects and arrays interactively.
How to Use
- 1Paste your JSON data or upload a .json file.
- 2Select a mode: Beautify / Minify / Validate / Tree View.
- 3In Beautify mode, choose your indent style (2 spaces, 4 spaces, or tab).
- 4Errors are highlighted in red with the line number.
- 5Copy the result or download it as a .json file.
Frequently Asked Questions
What is JSON formatting?
JSON formatting (also called beautifying) adds indentation and line breaks to make JSON data human-readable. It doesn't change the data itself, just its visual presentation.
What's the difference between Minify and Beautify?
Beautify adds whitespace and indentation for readability. Minify removes all unnecessary whitespace to reduce file size. Use Minify for API responses or config files in production.
Why should I validate JSON?
Invalid JSON syntax can cause API failures or program crashes. Validating before sending or saving catches syntax errors early and saves debugging time.
How does Tree View work?
Tree View renders JSON as an expandable/collapsible tree structure. Click any node to expand or collapse it. It's great for navigating deeply nested JSON objects.
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