JSON Formatter
Clean up minified or messy JSON with a fast browser-based formatter that keeps data local.
- Beautify minified payloads instantly.
- Keep formatting local in the browser.
- Prepare cleaner diffs, reviews, and docs.
Before
{"user":{"id":1042,"name":"Dana","roles":["admin","editor"],"active":true}}After
{ "user": { "id": 1042, "name": "Dana", "active": true } }
Practical guide
Build, validate, and reuse JSON with less friction.
A focused walkthrough for deciding when the tool fits your workflow.
The JSON Formatter instantly converts minified or inconsistently indented JSON into clean, readable output — directly in your browser with no data sent to a server. Whether you're inspecting a raw API response, reviewing a config file, or preparing a payload for documentation, formatted JSON is faster to read, easier to diff, and less likely to hide bugs.
How to use the JSON Formatter
- Paste your JSON into the editor. Minified, partially formatted, or multi-line input all work.
- The formatter applies consistent 2-space indentation automatically as you type or paste.
- Review the output in the right panel — nested objects and arrays are indented at the correct depth.
- Copy the formatted result or continue working with it in the JSON Diff Viewer or JSON Validator.
What it fixes
- Minified one-liners that are impossible to scan manually
- Mixed indentation (tabs and spaces in the same file)
- Collapsed nesting where it's unclear where one object ends and another begins
- Payloads copied from terminal output or curl responses that arrive unformatted
- Config files hand-edited by multiple people with inconsistent style
Before and after
Before — a minified API response:
{"user":{"id":1042,"name":"Dana","roles":["admin","editor"],"settings":{"theme":"dark","notifications":true}}}After — formatted with consistent indentation:
{
"user": {
"id": 1042,
"name": "Dana",
"roles": [
"admin",
"editor"
],
"settings": {
"theme": "dark",
"notifications": true
}
}
}The structure becomes immediately readable. roles is clearly an array of two strings; settings is a nested object with two fields. None of that is obvious in the minified version.
When to use it
Before code review — format both the old and new payload before pasting into a PR description. Reviewers shouldn't have to mentally parse minified JSON to understand what changed.
After copying a curl response — terminal output is often minified. Paste it into the formatter before starting any inspection or debugging work.
Before running a diff — the JSON Diff Viewer produces more accurate, readable results when both inputs share the same indentation style. Format both sides first.
Before writing documentation — minified JSON in docs is a reader experience problem. Format once, paste clean output into your README or Confluence page.
To understand the performance trade-offs between compact and readable JSON, see Pretty vs Minified JSON.
Questions about JSON Formatter
Everything you need to know before you start.
No. Formatting only changes whitespace — indentation and line breaks — that exists outside of string values. The data itself is identical whether JSON is pretty-printed or minified. Every parser produces the same result from both forms.
Formatting (or beautifying) JSON rearranges whitespace for readability. Validating JSON checks whether the syntax is correct according to the JSON specification. You can format valid JSON, but you cannot format invalid JSON — the formatter must parse it first. JSON Prism validates before formatting.
Yes. JSON Prism's JSON Formatter runs entirely in your browser — no installation, no sign-up, no server upload. Paste your JSON, click format, and copy the result. Your data never leaves your machine.
Use JSON.stringify(data, null, 2) — the third argument sets the indent size. Pass 2 for two spaces, 4 for four spaces, or a string like '\t' for tabs. To minify, use JSON.stringify(data) with no third argument.
JSON Formatter, free & private.
No account needed. Your JSON never leaves your browser.
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