Does minifying change my numbers?

No. `1.0` stays `1.0` and a twenty-digit identifier keeps its digits. That is not the default behaviour of a minifier built on parse-then-print — there, `1.0` becomes `1` and long integers are rounded. Here each number is copied as the text it is.

Why is my output barely smaller?

Because indentation was most of what could go. Key names, string values and structure are the document; shortening them would be changing it. If the goal is transfer size, gzip or brotli does far more — it finds the repetition in your key names, which no minifier may remove.

Should I minify JSON before storing it?

Only if something reads it by machine. A configuration file a person will open again is worth the indentation, and a build step can minify on the way out. Minified JSON in a repository is a file nobody will review properly.

JSON Minifier — Fewer Bytes Over the Wire

Strip whitespace from JSON. Numbers keep their written form and strings keep their escapes, so the payload gets smaller and stays the same.

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JSON input

JSON output

What this tool does

It removes the whitespace between tokens. Nothing else.

{
  "id": 12345678901234567890,
  "ratio": 1.0
}

{"id":12345678901234567890,"ratio":1.0}

Note what did not happen: 1.0 did not become 1, and the identifier did not lose its last digits. A minifier built the obvious way — parse to a value, print it back — does both, because a JavaScript number is a double-precision float that holds about fifteen digits and does not remember decimal points.

Here every number is copied as the text it is.

What it will not do

Shorten key names. They are the document.

Reorder anything. Key order is not meaningful to a JSON parser, but it is meaningful to the next person who reads a diff of this file.

Strip string escapes. \u00e9 and é are the same string, and rewriting one into the other changes the bytes for no benefit you asked for.

How much smaller, honestly

Indentation is typically a tenth of a formatted document, sometimes less. That is the whole prize.

If you are sending JSON over HTTP, compression does much more: gzip finds the repetition across your key names — "name" appearing five hundred times — which no minifier is allowed to touch. Minify for a file you embed or store; compress for the wire; do both if it matters.

Private by design

Everything runs locally in your browser with JavaScript. Your data is never uploaded, which makes the tool safe for sensitive content, and it keeps working offline.

Frequently asked questions

Does minifying change my numbers?: No. `1.0` stays `1.0` and a twenty-digit identifier keeps its digits. That is not the default behaviour of a minifier built on parse-then-print — there, `1.0` becomes `1` and long integers are rounded. Here each number is copied as the text it is.
Why is my output barely smaller?: Because indentation was most of what could go. Key names, string values and structure are the document; shortening them would be changing it. If the goal is transfer size, gzip or brotli does far more — it finds the repetition in your key names, which no minifier may remove.
Should I minify JSON before storing it?: Only if something reads it by machine. A configuration file a person will open again is worth the indentation, and a build step can minify on the way out. Minified JSON in a repository is a file nobody will review properly.