Minify an indented config
Input
{
"message": "hello world",
"count": 2
}Example output
{"message":"hello world","count":2}JSON Minifier
JSON & Data100% Client-SideReady
JSON
0 lines0 chars
0 B / 4.77 MB
Read-only
0 lines0 chars
0 B
About this tool, examples & FAQ
Parse valid JSON and re-serialize it without structural whitespace, entirely in your browser. Spaces inside string values are preserved, and invalid input produces an actionable syntax error with line and column.
Key facts
| Accepted input | JSON text: objects, arrays, strings, numbers, booleans, or null |
|---|---|
| Operation | Single fixed operation with no options: parse, then serialize without extra whitespace |
| Max input size | 5 MB |
| Execution deadline | 2 s |
| Processing location | Browser-only: pasted input is not uploaded |
How to use
- Paste your formatted or spaced JSON into the editor.
- Click 'Run' to minify the JSON.
- If the input is invalid, read the reported line and column, fix the syntax error, and run again.
- Use 'Copy' or 'Download' to retrieve the compact output, or use 'Send To' to pipe it into another utility such as Base64 or Hash.
Example
Edge cases
Spaces inside strings
Whitespace characters inside string values are preserved; only whitespace between structural tokens is removed. Escape spellings inside strings may still be rewritten (see below).
Escape sequences
Escape sequences inside strings may be rewritten even though the parsed character is unchanged: for example, "\u0041" becomes "A".
Duplicate keys
Duplicate object keys are not reported: the last value wins during parsing, matching JSON.parse behavior.
Number precision
Values follow standard JavaScript JSON precision: integers beyond 2^53 - 1 may lose least-significant digits, and out-of-range literals such as 1e999 do not survive the round trip.
How it works
- Rejects empty or whitespace-only input before parsing.
- Parses the input with the platform JSON parser and converts engine diagnostics into line and column indicators.
- Serializes the parsed value with no indentation or extra whitespace.
- Executes inside a Web Worker bounded by the tool deadline.
Related workflows
JSON Formatter
Prettify, indent, and format JSON strings with customizable indentation and key sorting.
JSON Validator
Validate JSON syntax, inspect structure, and diagnose syntax errors with line and column diagnostics.
Base64 Encoder / Decoder
Encode UTF-8 text to standard or URL-safe Base64 and decode Base64 back to text.
Hash Generator
Generate cryptographic hashes and message digests including SHA-256, SHA-512, SHA-384, SHA-1, and MD5 for text payloads.
Frequently asked questions
Is minification the same as compression?
No. Minification removes unnecessary whitespace from the JSON text. It does not apply gzip or Brotli compression, and it does not change HTTP headers.
Does minification change my data?
The parsed data is preserved, with three caveats: whitespace inside strings is kept but escape sequences may be rewritten, duplicate keys collapse to the last value, and numbers follow standard JavaScript JSON precision.
What happens with invalid JSON?
Minification fails with an actionable syntax error reporting line and column. Fix trailing commas, single quotes, comments, or unclosed braces and run again.
Should I still use gzip or Brotli for transport?
Yes. Minifying shrinks the payload text, and transport compression such as gzip or Brotli shrinks it further on the wire. They complement each other.
How do I make minified JSON readable again?
Paste the compact output into the JSON Formatter and choose 2-space, 4-space, or tab indentation to pretty-print it.
Is my pasted input uploaded anywhere?
No. Minification runs inside an isolated Web Worker in your browser, and pasted input is not uploaded for processing. The browser still requests site assets from the host; clipboard, downloads, and analytics are separate boundaries.
References
- RFC 8259 — The JavaScript Object Notation (JSON) Data Interchange Format — JSON syntax, values, and data model