Online JSON Diff Checker
Paste two JSON objects and instantly see which keys were added, removed, or changed — displayed in a structured, readable format.
Open the Tool — Free & InstantYour data never leaves your browser
No server processing
All diffing runs locally in your browser using JavaScript. Zero data transmitted.
No logging or storage
We do not store, log, or read your content. Nothing is saved anywhere.
Safe for sensitive content
Confidential code, config files, API keys — safe to compare here.
PII detection on share
Before any share link is generated, your content is scanned for emails, API keys, and tokens — with options to redact or encrypt.
Features
- ✓Structured key-by-key JSON comparison
- ✓Nested object and array diffing
- ✓Added, removed, and changed keys clearly labeled
- ✓Falls back to text diff for non-JSON content
- ✓Syntax highlighting for JSON
- ✓Shareable links for any JSON diff
- ✓100% in-browser, JSON never leaves your machine
- ✓No formatting required — handles minified JSON
Frequently Asked Questions
How do I compare two JSON objects online?
Paste the first JSON in the left panel and the second in the right panel. If both are valid JSON, a "JSON" view tab appears — click it to see a structured key-by-key comparison with added keys in green, removed in red, and changed values highlighted.
Does it support nested JSON objects?
Yes. The JSON diff recursively compares nested objects and arrays, showing exactly which nested keys changed.
What if my JSON is minified or poorly formatted?
No problem. The tool parses the raw JSON regardless of formatting — you do not need to pretty-print it first.
Is my JSON data private?
Completely. All comparison happens in your browser using JavaScript. Your JSON is never sent to a server. It is safe to use with API responses, config files, or any sensitive data.
Can I compare JSON files instead of pasting?
Yes. Drag and drop a .json file onto either panel or use the File button to upload it.