JSON Compare
Compare two JSON objects and list their differences
What is a JSON Compare?
I built JSON Compare to help you spot every difference between two JSON objects. Instead of manual scanning, this tool lists keys that differ, missing fields, type mismatches, and value changes at each path.
What Does Our JSON Compare Do?
When you paste two JSON strings and click Compare JSON the script parses both inputs, then recursively traverses their structure. It reports differences in types, missing keys, mismatched values, and array length discrepancies. All work happens in your browser, so your data stays private.
What to Expect When Using This Tool
You will see three panels labeled JSON Input 1, JSON Input 2, and Differences. Paste your JSON objects into the first two panels, click Compare JSON, and a list of differences appears in the third panel. If the JSON is invalid you receive a clear alert. Clear All resets all fields.
Common Use Cases
- Verifying API responses against expected schema
- Comparing configuration files before deployment
- Spotting unintended changes in data payloads
- Debugging mismatches in test fixtures
- Auditing differences between environment-specific settings
Input and Output Examples
Example 1
Input 1:
{"user":{"id":1,"name":"Alice"},"active":true}
Input 2:
{"user":{"id":"1","name":"Alice"},"active":false,"role":"admin"}
Differences:
user.id: type differs (number vs string)
active: value differs (true vs false)
role: missing in first JSON
Example 2
Input 1:
[1,2,3]
Input 2:
[1,2,4]
Differences:
[2]: value differs (3 vs 4)
Frequently Asked Questions
What if one JSON is invalid?
You will see an alert specifying which JSON failed to parse and why. Fix the syntax before comparing.
Does it handle nested structures?
Yes. It traverses objects and arrays at any depth and reports differences with full paths.
Can I compare large JSON files?
It handles moderate-size JSON well. Very large files may impact browser performance.
Are differences case-sensitive?
Yes. Key names and string values are compared exactly.
Will it reorder keys?
No. It compares structure and values but does not modify input order.
How do I copy the list of differences?
Select the Differences panel and use your device’s copy command.
Can I use this on mobile?
The layout stacks panels for easy use on phones and tablets.
Does my data leave my browser?
No. All comparison happens locally, nothing is sent to a server.
Can I clear all fields at once?
Yes. Click Clear All to reset both inputs and the output.
Benefits of Using JSON Compare
- Quickly identify missing or changed fields
- Detect type mismatches before code breaks
- Streamline debugging of API and config issues
- Ensure consistency across environments
- Save time over manual comparison
Best Practices
- Validate JSON syntax before comparing
- Use prettified JSON for easier input
- Compare small chunks if performance slows
- Keep a copy of original data for reference
- Integrate into review process for schema changes
Getting Started
- Paste the first JSON into the JSON Input 1 box
- Paste the second JSON into the JSON Input 2 box
- Click Compare JSON
- Review the list of differences in the Differences box
- Click Clear All to start a new comparison
- Use the results to correct or update your data!