JSON Formatter
Validate and beautify JSON with precise line-and-column error reporting; minify to a single line in one click.
>_ USAGE GUIDE
Paste a JSON string from an API response or a config file into the input, and the readable, indented version appears immediately. When the input has a syntax error — a missing comma, an extra bracket, an unquoted string — the tool does not just report a vague "parse failed". It tells you the exact line and column of the error and highlights the characters around it, so you fix the problem instead of hunting for it.
- Paste your JSON: press Ctrl+Enter (or the Format button) to validate and beautify in one go
- Fix flagged errors: jump straight to the reported line and column and correct the nearby characters
- Beautify: nested objects are expanded with 2-space indentation, so the structure stays readable at any depth
- Minify: strip every space and newline into a single compact line, ideal for configs, logs, or request payloads
Everything runs in your browser: parsing, formatting, and minifying happen locally with zero uploads. JSON containing API keys, tokens, or real user data never leaves your device, and the page keeps working offline once loaded.
>_ FAQ
Q1 · Why does my JSON keep failing validation?
The most common causes are a trailing comma after the last key, single quotes instead of double quotes, and unescaped newlines or quotes inside a string value. Paste the JSON into this tool and the error is pinpointed to a specific line and column — jump there and check the surrounding characters. It is far faster than scanning line by line yourself.
Q2 · What is the difference between formatting and minifying JSON?
Formatting expands the JSON with 2-space indentation, one key-value pair per line, which makes it easy for humans to read and debug. Minifying removes all whitespace and line breaks to produce a single compact line with the smallest possible size, which suits config files, API payloads, and database fields. Read in formatted form, transmit and store in minified form.
Q3 · Is it safe to paste JSON that contains sensitive data?
Yes. All parsing and formatting run entirely in your browser — the content is never transmitted over the network and nothing is stored. Payloads containing API keys, tokens, or real user data can be pasted with confidence, and the tool also works offline.
Q4 · Can it handle large JSON files of several megabytes?
Yes, parsing a few MB of JSON locally in the browser is no problem. For extremely large files in the tens of megabytes, memory usage can become noticeable — preprocess with a command-line tool such as jq first, or extract just the section you need. Typical API responses and config files are well within range.
Q5 · Why does JSON copied from JavaScript code fail validation?
JSON is stricter than JavaScript object literals: keys and string values must use double quotes, comments are not allowed, and trailing commas are forbidden. Copying an object straight out of JS code therefore often fails validation. Fix those syntax differences — or let the error locator point you to the first offender — and the JSON will parse cleanly.