About this tool
This formatter uses the browser's native JSON.parse — the strictest, fastest JSON implementation there is. When parsing fails, the tool converts the raw error position into a precise line and column, so a missing bracket in a 5,000-line API response takes seconds to find instead of minutes. Formatting and minifying are one keystroke apart, with 2-space, 4-space or tab indentation.
Everything runs client-side: the API responses and configs you paste never leave your machine — safe even for payloads with tokens or customer data. Struggling with a recurring error? See the guide to common JSON errors, or find more free tools at dec0de.dev.
Developers reach for a JSON formatter dozens of times a day: to read a minified API response, to pretty-print a config file, to spot the stray comma breaking a build, or to shrink a payload before shipping it. Beautifying restores indentation and line breaks so the structure is obvious; minifying strips every optional space to cut bytes. Validation is the quiet hero — it turns a vague "invalid JSON" into a precise line-and-column so the fix takes seconds, not minutes.
Frequently asked questions
Why does my JSON say "Unexpected token"?
Usually a trailing comma, a missing comma or brace, or single quotes instead of double quotes. The error here shows the exact line and column so you can jump straight to it.
What is the difference between formatting and minifying?
Formatting (pretty-print) adds indentation and line breaks so JSON is readable; minifying strips all whitespace to make the file as small as possible for transport. The data is identical either way.
Are comments or trailing commas allowed?
Not in standard JSON. The spec has no comments, no trailing commas and requires double quotes. This tool validates strict JSON — remove those before it will parse. Formats like JSON5 or JSONC allow them, but they are not plain JSON.
Is my JSON kept private?
Yes. Everything runs in your browser. The API responses and configs you paste never leave your machine — safe even for payloads containing tokens or customer data.
Can it handle large JSON files?
Yes. It parses multi-megabyte JSON directly in the browser, with no upload. Very large documents depend on your device’s memory, but multi-MB payloads are handled comfortably.