JSON Formatter & Validator
Beautify, minify and validate JSON in one click — with precise error locations, right in your browser and nothing uploaded.
Quick answer
A JSON formatter turns messy, minified or hand-typed JSON into clean, indented, readable text — and tells you instantly whether it is valid. Paste your JSON above, then choose Format / Beautify (2 or 4 spaces) to pretty-print it, Minify to compress it onto one line, or Validate to check it. If something is wrong, you get the exact error message and its approximate line and column. Everything runs privately in your browser.
Why format and validate JSON
JSON is the everyday language of APIs, config files and data exchange, but it is unforgiving: a single missing comma or stray quote makes the whole document invalid. Formatting reveals the structure so you can scan nesting, spot duplicated keys and understand a response at a glance. Validation catches the small syntax mistakes — trailing commas, unquoted keys, single quotes — before they break your code or a webhook. Because this tool parses with the browser's own engine, what it accepts is exactly what your JavaScript will accept.
Beautify, minify and indentation
Beautifying adds line breaks and indentation so nested objects and arrays are easy to follow; pick 2 spaces for compact readability or 4 spaces when you want more visual separation. Minifyingdoes the opposite, stripping every optional space and newline to produce the smallest valid payload — useful for reducing bandwidth, embedding JSON in a string, or fitting it into a query. You can move between the two freely without retyping anything.
Reading the error message
When parsing fails, the tool shows the raw parser message and an approximate line, column and character position. Jump to that spot in your source and look just before it: the most common culprits are a comma missing between two items, an extra comma after the last item, keys or strings wrapped in single quotes instead of double quotes, or unescaped line breaks inside a string. Fix the first error and re-validate, since one mistake can mask the next.
Private by design
API responses and config files often contain secrets — tokens, keys, personal data. Everything here is processed entirely on your own device with client-side JavaScript, so you can safely paste sensitive payloads. Nothing is sent to a server, stored or logged, and the tool keeps working even offline.
Frequently asked questions
Is my JSON uploaded to a server?+
No. The formatter runs entirely in your browser using the native JSON parser. Nothing you paste is uploaded, logged or seen by anyone — it never leaves your device, so it is safe for API keys, tokens and confidential payloads.
What is the difference between beautify and minify?+
Beautify (or format) adds indentation and line breaks so the JSON is easy to read, using either 2 or 4 spaces. Minify strips all optional whitespace to produce the smallest valid JSON on a single line, which is ideal for sending over the network or embedding in code.
How does it help me find errors?+
When the JSON can't be parsed, the tool shows the browser's parse error message plus an approximate line, column and character position. That points you close to the problem — usually a missing comma, an extra trailing comma, unquoted keys, or single quotes where double quotes are required.
Why must JSON keys use double quotes?+
The JSON specification only allows double quotes around keys and string values, and forbids trailing commas and comments. JavaScript object literals are more relaxed, which is why code that looks fine can still fail to parse as JSON. This validator follows the strict standard.
Is there a size limit?+
There is no fixed limit. Because everything is processed on your own device, you can format short snippets or large API responses; very large documents simply use a little more memory and take a moment longer.