JSON Formatter — Format, Minify & Validate JSON in Seconds
Working with JSON is part of daily development: API responses, config files, and log dumps often come as a single unreadable line. Manually adding line breaks and indentation is tedious and error-prone. A JSON formatter lets you paste raw or minified JSON and get back properly indented, human-readable output in one click. You can also minify JSON to reduce payload size for production, or validate that a string is legal JSON before it breaks your pipeline. This tool runs entirely in your browser, so your data never leaves your machine. Whether you're debugging an API, cleaning up an export, or preparing a payload for documentation, a reliable formatter saves time and reduces mistakes. Many teams rely on JSON for configuration and API contracts; having a fast, local formatter avoids dependency on external services and keeps sensitive payloads private. The combination of format, minify, and validate in one place means you rarely need to switch tools or write custom scripts.
What Does This Tool Do?
This JSON formatter does three things: format (pretty-print), minify, and validate. When you paste JSON into the input area, you can click Format to turn a single-line or messy blob into readable text with consistent indentation. You choose 2 or 4 spaces for the indent level, and the tool uses JavaScript's native JSON.parse and JSON.stringify so the result is standard-compliant. Minify does the opposite: it parses the input and outputs a single line with no unnecessary whitespace, which is useful for request bodies or stored config where size matters. Validate parses the input and, if it's valid JSON, shows the formatted result; if not, it shows the parser error message so you can fix the problem. All processing happens in the browser, so no data is sent to any server. The output area is read-only so you can select and copy without accidentally editing. Indentation is applied consistently so that nested objects and arrays are easy to follow, and the parser error messages help you locate trailing commas, missing quotes, or invalid escape sequences quickly.
How to Use It (Step-by-step)
Paste or type your JSON into the Input text area. It can be already formatted, minified, or pasted from a log or API response.
If you want pretty-printed output, select the indent size (2 or 4 spaces) using the buttons.
Click Format to get indented, readable JSON in the Output area; click Minify to get a single-line version; or click Validate to check syntax and see formatted output or an error.
If the output looks correct, use the Copy button to copy it to the clipboard.
Use Clear to reset both input and output when you're done or starting with new data. If you see an error message, fix the issue in the input (common problems include trailing commas, single quotes instead of double, or unquoted keys) and try again.
Key Features & Use Cases
- Client-side only: no data is sent to a server; everything runs in your browser.
- Format with 2 or 4 space indentation for consistent, readable output.
- Minify to a single line for smaller payloads and production use.
- Validate and see parse errors when JSON is invalid.
- Copy the result to the clipboard with one click.
- Pretty-print API responses in the Network tab or from curl for easier debugging.
- Minify JSON before sending it in a request or storing it in a config file.
- Validate config files or environment payloads before deployment.
- Inspect minified logs or database dumps without leaving your browser.
- Prepare JSON samples for documentation or team handoffs.