JSON Minifier

Paste any JSON, get the smallest valid form back. Validates as it minifies — invalid input shows the parse error.

When minified JSON helps

• Inline data attributes. data-config='{...}' in HTML — every byte counts.
• localStorage / IndexedDB. Browser quotas are bytes; compact JSON fits more.
• postMessage / WebSocket payloads. Smaller payloads = faster handshakes, especially across slow links.
• QR codes. JSON in a QR code only fits if it's tiny — minify aggressively, and consider YAML if it's still too big.
• Inline SVG metadata, IPFS pins, blockchain calldata. Anywhere bytes are charged for.

When minified JSON hurts

• Logs. Minified is unreadable. Pretty-print logs in dev, minify only at the persistence boundary if needed.
• Diffs. A minified JSON change shows up as one giant line in git diff. Pretty-print files that humans review.
• HTTP responses with gzip / brotli. Compression nullifies most of the savings; the readability cost in DevTools is real.

How much it saves, by example

Minify + gzip is not double savings

A common misconception: minifying before gzip / brotli doesn't multiply. Compression algorithms recognize whitespace patterns and compress them efficiently. Minify-then-compress is typically only 2-5% smaller than indent-then-compress. The decision is about source-level size (where minification dominates), not transport size.

What this tool doesn't do

• It doesn't strip data — only whitespace. To remove keys, use a JSON-aware tool like jq.
• It doesn't validate against a schema. For that, you need JSON Schema tooling.
• It doesn't handle JSONC (JSON with comments). Strict JSON only.

Programmatic equivalent

// JavaScript / TypeScript
JSON.stringify(JSON.parse(input));

// Python
import json
json.dumps(json.loads(input), separators=(",", ":"))

// jq (CLI)
echo "$INPUT" | jq -c .

// Go
import "encoding/json"
out, _ := json.Marshal(parsed)