Home

API Response Comparator

API Response Comparator compares JSON responses from Dev, QA, and Prod without a one-off script. Provide any two or all three responses, then inspect value and API contract changes in a table or color-coded JSON tree.

Paste, upload, fetch, or import cURL
  -> Parse JSON -> Flatten paths -> Compare with first populated environment
  -> Filter, inspect, copy, or export differences

What it detects

Result	Meaning
ADDED	A path is missing from the baseline and present downstream.
REMOVED	A path is present in the baseline and missing downstream.
CHANGED	Both values have the same JSON type but different content.
TYPE_CHANGE	Both values exist but have different JSON types.

Added, removed, and type-changed fields also trigger an API contract warning.

Choose where to start

• Use the application: Getting Started, then User Guide.
• Understand a result: Comparison Model.
• Run an extension: Browser Extensions.
• Review network behavior: Security and Privacy.
• Work on the project: Architecture and Development Guide.
• Resolve a problem: Troubleshooting.

Highlights

• Paste JSON, upload files, fetch HTTPS endpoints, or import cURL.
• Ignore volatile fields manually or generate scored suggestions.
• Filter by type and search paths without changing the exported result.
• Copy JSON or download JSON and styled Excel reports.
• Use table or collapsible tree views in light or dark mode.
• Reset inputs, results, filters, uploads, and in-flight requests at once.

Browser extensions

Available for Firefox, Chrome, and Edge. Safari source is included for packaging on macOS.

Project links

• Source
• Issues
• Contributing
• MIT license