JSON Minifier

Paste JSON on the left; the compact, whitespace-free version appears on the right as you type. Nothing leaves your browser.

What minifying JSON does

Minification removes every byte that the JSON grammar treats as optional: spaces, tabs and newlines between tokens. It does not change keys, values, or ordering, and it never removes data. The result parses to exactly the same value as the input.

When to minify

• API responses and request bodies — fewer bytes over the wire, faster for mobile clients.
• Config shipped inside a bundle — JSON embedded in JavaScript or HTML counts toward page weight.
• Storage — logs, caches, and localStorage entries are often size-limited.

When not to minify

Files that humans edit by hand: configuration in a repository, fixtures, sample payloads in documentation. Minified JSON is miserable to diff and review. Keep the source pretty and minify at build time instead. Need the readable form back? Use the auto-formatter.

How much does it save?

For a typical 4-space-indented document, minifying removes 20–40% of the bytes. With gzip or Brotli enabled on the server the gap shrinks, because compression already squeezes repeated whitespace, but it is still free savings and a smaller buffer to parse on the client.

Does it validate too?

Yes. The input must be strict JSON (RFC 8259). If it is not, the status line shows the error with a line and column so you can fix it. For JSON with comments or trailing commas, run it through the formatter first — its lenient parser repairs those.