Compare API responses
Check whether a backend response changed between environments, versions, or test runs.
Free browser tool
JSON Diff
The JSON diff tool compares two JSON values and reports basic differences between paths, keys, array positions, and values. It is useful when checking API changes, configuration updates, webhook payloads, feature flag files, or copied examples that look similar but behave differently.
This is intentionally a practical text summary rather than a heavy visual diff. The tool validates both inputs first, then lists missing paths and changed values using readable JSON path notation. It works best for debugging small to medium JSON documents.
JSON diff
Compare two JSON inputs and list changed, missing, or added paths.
What this tool does
JSON documents can look almost identical while containing a small change that matters. A renamed key, missing field, changed boolean, reordered array, or nested value can affect an API contract, feature flag, or configuration file. The JSON Diff tool validates two inputs and reports basic differences using readable JSON paths.
This diff is intentionally practical rather than decorative. It does not try to render a full code editor comparison. Instead, it lists what changed, what only exists in A, and what only exists in B. That makes it useful for quick debugging when you need to understand why two payloads behave differently.
Arrays are compared by index, and objects are compared by key. If an array is reordered, several differences may appear even when the same values are present. For many API and config workflows, index-based comparison is still the clearest first pass because order often matters.
Common use cases
Review configuration changes
Find differences between two JSON config files before deploying a settings update.
Debug feature flags
Compare flag payloads to see whether targeting, variants, or booleans changed unexpectedly.
Inspect webhook versions
Compare webhook examples from different events or providers to understand structural differences.
Example before and after
The diff reports that enabled changed from true to false and trial only exists in JSON B.
JSON A
{
"enabled": true,
"plan": "free"
}JSON B
{
"enabled": false,
"plan": "free",
"trial": true
}How to use
- Paste JSON A and JSON B into the two textareas.
- Click Compare JSON.
- Review missing paths and changed values in the result.
Common errors
Comparing invalid JSON
Both inputs must be valid JSON. Run validation first if either side fails to parse.
Ignoring array order
Arrays are compared by position. Reordered arrays can show many path changes.
Comparing formatted text only
Whitespace is not a JSON value. The diff compares parsed values, not indentation.
Missing nested context
A change deep in an object appears as a path such as $.user.profile.name. Read the full path before editing.
Why use this tool
Spot API response changes quickly.
Compare config versions without extra software.
Find changed values in nested JSON.
Best practices
Format both inputs first
Readable JSON helps you understand the diff output and inspect the original payloads.
Compare realistic samples
Use payloads from the same endpoint or config area so differences are meaningful.
Watch array reordering
If order should not matter, sort arrays before comparing or compare specific object keys.
Copy the diff into bug reports
A short list of changed paths is useful context for teammates reviewing a behavior change.
Related JSON tools
Related guides
How to compare two JSON files
A practical guide to comparing JSON payloads, configs, arrays, and API responses without getting distracted by formatting.
Best practices for working with API responses
API responses are easier to debug when you validate syntax, format payloads, inspect errors, and compare changes deliberately.
Common JSON syntax errors
Trailing commas, bad quotes, comments, unclosed brackets, and undefined values are the JSON mistakes developers hit most often.
FAQ
Does JSON Diff validate both inputs?
Yes. Both JSON documents must parse successfully before comparison.
Does it show a side-by-side visual diff?
No. It shows a clear list of changed, added, and missing paths.
Can it compare arrays?
Yes. Arrays are compared by index, so reordered arrays can show many changes.
Is the comparison client-side?
The tool runs in your browser and does not require login, a database, or server-side processing.