Read API responses
Beautify compact response bodies while debugging integrations, webhooks and command-line output.
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Format tool
JSON Formatter & Minifier
Format or minify JSON online in your browser. Beautify compact payloads, validate syntax and keep data private.
✓ Free to use✓ No signup✓ Runs locally
51 bytes · local only
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Processed entirely in this tab
Your input and result are not sent to JSON Hearth or stored on a server.
When to use it
What Formatter helps you do
Formatting adds indentation and line breaks so a compact payload is easier to read. Minifying removes unnecessary whitespace for copying or transport.
Prepare configuration
Normalize indentation before reviewing or committing JSON configuration files.
Reduce whitespace
Minify valid JSON when you need a compact representation for logs, examples or payloads.
Important limitations
What to check before using the result
- Formatting requires syntactically valid JSON and does not silently repair malformed input.
- Formatting and minification serialize a parsed JavaScript value. Large numbers can lose precision, duplicate property names are collapsed and numeric literals beyond JavaScript's finite range can become null.
- Keep the original when exact digits, duplicate names or source representation matter. Minification is not compression or lossless text editing.
Common questions
About Formatter
Does formatting change JSON values?
It can when parsing changes the source value. For example, the number 9007199254740993 rounds in JavaScript, and repeated object names retain only the last value. Use strings or a lossless parser when exact numeric digits must survive, and keep the original document.
Can this formatter fix invalid JSON?
Use the JSON repair tool for common syntax mistakes. Review repaired output before relying on it.