JSON Formatter, Validator & Viewer

This online JSON formatter helps you turn messy or minified JSON into clean, readable text in one click. Paste an API response, a config file, or a log line into the box above and the tool will format and beautify it instantly using your choice of 2 spaces, 4 spaces, or tabs. If you need to go the other way, the JSON minify button strips every unnecessary character to produce the smallest possible single-line payload. There is no signup, no upload, and nothing leaves your browser, so it works as a private, fast JSON beautifier for sensitive data.

Beyond formatting, the built-in JSON validator checks your input the moment you type. When the JSON is well formed you get a green valid badge plus quick stats: the top-level type, the number of keys or items, the nesting depth, and the byte size. When something is wrong, the JSON lint engine surfaces a clear error message and an approximate line and column so you can jump straight to the problem. Most JSON syntax errors come from trailing commas, single quotes instead of double quotes, unclosed brackets, or unescaped characters, and the reported location makes them easy to fix.

To explore large or deeply nested payloads, switch the output to the JSON tree viewer. Objects and arrays become collapsible nodes you can expand and collapse with a chevron, and every value is color coded by type so the structure is easy to scan. Pretty print mode shows the same data as cleanly indented, syntax-highlighted text that you can copy to your clipboard or download as a .json file. Whether you searched for a JSON formatter online, a JSON pretty print tool, a JSON viewer, or a way to format JSON online, this single page covers formatting, validation, minification, and visual exploration without installing anything.

Working with data and APIs? Try our LLM token counter to estimate how much your JSON payloads cost across GPT, Claude, and Gemini.