JSON Formatter
Tip: Press Ctrl+Enter to format
Paste Your JSON
Enter or paste a JSON string in the input panel and the formatter will instantly validate, format, and display it with syntax highlighting.
How to Use This Formatter
Paste or Upload Your JSON
Copy your JSON string from an API response, config file, or any source and paste it into the input textarea. Alternatively, click 'Upload File' to import a .json file directly from your computer. The formatter begins processing automatically as you type.
Choose Formatting Options
Select your preferred indentation (2 spaces for compact output, 4 spaces for extra readability, or tab for traditional formatting). Enable 'Sort keys' if you want all object keys ordered alphabetically — useful when comparing two JSON objects or generating deterministic output.
Review the Result
A green badge confirms the JSON is valid. If there is a syntax error, a red badge shows the exact line and column number along with a plain-English error description. Use the 'Auto-Fix' button to automatically repair common issues like trailing commas, single quotes, and unquoted keys before formatting.
Copy, Download, or Explore
Switch between the Formatted view (syntax-highlighted code), Tree View (interactive collapsible hierarchy), and CSV tab (for arrays of objects). Copy the output to clipboard or download it as a .json or .csv file. Check the Size Comparison bars to see how much minification reduces your payload.
Frequently Asked Questions
Is my JSON data safe to paste here?
Yes, completely. The JSON Formatter runs entirely in your browser using client-side JavaScript. Your data is never sent to any server, never stored, and never logged. Everything happens locally on your device — even if you disconnect from the internet after loading the page, the formatter continues to work. This makes it safe to use with API tokens, database payloads, internal configuration files, or any sensitive data you would not want to transmit over a network.
What does the Auto-Fix button do?
Auto-Fix applies a sequence of heuristic repairs to malformed JSON before parsing. It handles the most common real-world issues: removing trailing commas (left over from JavaScript object literals), converting single quotes to double quotes, adding missing quotes around unquoted object keys, replacing Python-style None/True/False with JSON null/true/false, stripping JavaScript-style comments (// and /* */), normalizing curly or 'smart' quote characters pasted from word processors, removing JSONP function wrappers, and converting newline-delimited JSON (NDJSON) into a valid JSON array. Auto-Fix is a best-effort tool — it works well for common cases but cannot repair severely corrupted data.
What is the difference between Format and Minify?
Formatting (also called beautifying or pretty-printing) adds indentation and line breaks to make JSON easy to read. It is ideal for development, debugging, and documentation. Minifying does the opposite: it removes all unnecessary whitespace — spaces, tabs, and newlines — producing the most compact possible representation of the same data. Minified JSON is faster to transmit over a network and uses less bandwidth, making it the preferred format for API responses in production. The two representations contain exactly the same data; only the formatting differs. Our Size Comparison bars show you numerically how much smaller the minified output is.
How does the Tree View work?
The Tree View renders your JSON as an interactive collapsible hierarchy. Each object and array is shown with a toggle arrow that expands or collapses its children. Clicking any node toggles it open or closed. By default, the first two levels are expanded so you can immediately see the top-level structure without being overwhelmed by deeply nested data. The Expand All and Collapse All buttons toggle the entire tree at once. Hovering over any node reveals a small copy icon that lets you copy just that node's value as formatted JSON — perfect when you need a specific nested object from a large response.
When does the CSV tab appear?
The CSV tab appears automatically when your JSON is a valid array of objects — a pattern returned by virtually every REST API that lists resources (users, products, orders, etc.). The converter extracts all unique keys across all objects as column headers, then maps each object's values to the corresponding columns. Nested objects within array items are serialized as JSON strings rather than flattened into sub-columns. The resulting CSV can be downloaded and opened directly in Excel, Google Sheets, or any spreadsheet application. If your JSON is a single object or contains non-object array elements, the CSV tab is hidden.
What indentation should I choose?
The choice depends on your use case and team conventions. Two spaces is the most popular choice in JavaScript, TypeScript, and JSON configuration files — it keeps files compact while still being readable. Four spaces is common in Python projects and some Java environments. Tabs are preferred by some teams because they allow each developer to configure their editor to display them at any visual width. When in doubt, check your project's .editorconfig or linting configuration. For sharing JSON in documentation or messages where visual alignment matters more than file size, 4 spaces tends to be the clearest. For production API responses, always use minification rather than any indentation.