JSON Minifier — Compact and Validate JSON Online
Parse and compact JSON in your browser. Compare the output size before using it in an API or asset.
Jump to tool ↓Frequently Asked Questions
JSON Minification for Performance Optimization
Paste valid JSON into the input panel. This tool parses it and writes compact JSON without indentation. For example, { "name": "Ada", "active": true } becomes{"name":"Ada","active":true}. Spaces inside string values remain part of the data.
The algorithm is simple: parse the JSON, then serialize without any formatting. In JavaScript:JSON.stringify(JSON.parse(input)) where the default serializer produces compact output. Parsing also collapses duplicate object keys and can normalize number notation. This is useful for generating a compact representation, but it is not a byte-preserving whitespace stripper.
Keep the readable source for review. If the JSON is sent over HTTP, compare the compressed response size after gzip or Brotli as well as the raw size. Compression can reduce the benefit of minifying.
Standards & References
Built and maintained by DevDecode. This tool processes your input in your browser; it is not uploaded for processing. Found an issue? Let us know.
Related Tools
Related Guides
JSON vs JSONL: Format, Examples, and When to Use Each
Compare JSON arrays and JSON Lines with valid examples, streaming code, common parsing errors, and a quick way to validate each format.
Data FormatsJSONL to JSON: Convert Lines into an Array Safely
Turn newline-delimited JSON into a JSON array with Python or Node.js, reject malformed lines, and avoid common blank-line and memory mistakes.
Data FormatsCan You Use Comments in JSON? (And What to Do Instead)
Standard JSON does not support comments. Learn why the spec excludes them, the common workarounds like JSONC and comment keys, and how to strip comments before parsing.
Data FormatsHow to Open a JSON File (Windows, Mac, and Browser)
Open a JSON file with a text editor, browser, or online viewer. Step-by-step instructions for Windows, Mac, and phones — plus the easiest way to read it formatted.