JSON Compare Tool

Diff two JSON documents side by side — find additions, deletions, and changes instantly

What Is JSON Comparison?

JSON comparison (or JSON diffing) analyzes two JSON documents and identifies every difference between them: keys that were added, keys that were removed, values that changed, array elements that shifted, and structural modifications at any nesting depth. The result is a visual diff report that highlights exactly what changed between two versions of a JSON document.

JSON comparison is essential for debugging API behavior changes, reviewing configuration updates, auditing infrastructure-as-code modifications, and verifying data migration results. Unlike plain text diff tools that compare line by line, a JSON-aware diff understands the document structure — it knows that reordering keys in an object is semantically meaningless, while reordering array elements is a real change. This structural awareness eliminates false positives and produces accurate, actionable diff results.

How to Compare Two JSON Documents

1. Paste the first JSON document (the original or base version) into the left editor panel
2. Paste the second JSON document (the modified or updated version) into the right editor panel
3. Click Compare to generate the structural diff
4. Review color-coded results: green for additions, red for deletions, yellow for changed values
5. Click individual diff entries to navigate directly to the changed node in each document

Why Use PinusX for JSON Comparison?

PinusX performs the entire diff computation in your browser with 100% client-side processing. Both JSON documents stay on your device — nothing is uploaded to any server. This is critical when comparing configuration files that contain API keys, deployment secrets, or database credentials. In November 2025, jsonformatter.org leaked over 80,000 user credentials that had been processed through their servers. PinusX eliminates this risk because the diff algorithm runs locally using JavaScript in your browser tab. Compare your production configs, infrastructure manifests, and private API responses with complete confidence that your data remains private.

Frequently Asked Questions

Does JSON compare detect key reordering?

Our tool is smart about key ordering. Since JSON objects are unordered by specification, simply rearranging keys is not reported as a change. Only actual data differences — different values, added keys, or removed keys — are highlighted. This prevents false positives when comparing JSON generated by different serializers.

Can I compare deeply nested JSON?

Yes. The diff engine recursively descends through every level of nesting. Changes inside objects within arrays within objects are detected and reported with their full path. There is no depth limit — even 20 levels deep, differences are found and highlighted.

How are array differences handled?

Array comparison checks elements by position. If element [2] in the left document differs from element [2] in the right document, that difference is reported. Added or removed array elements at the end are detected as additions or deletions. For complex array diffing, keys within array objects help match corresponding entries.

Can I ignore specific fields during comparison?

Currently the tool compares all fields. To ignore fields like timestamps or auto-generated IDs, you can remove them from both documents before comparing, or use the JSON sort keys tool first to normalize both documents and focus on structural differences.

What file size can I compare?

Since processing is client-side, you can compare JSON documents up to several megabytes each. Both documents need to fit in browser memory simultaneously. For typical development workflows with configuration files and API responses under 5MB, the comparison is instant.

Your data never leaves your browser. 100% client-side processing.