JSON Diff

What is JSON Diff?

JSON Diff compares two JSON documents and highlights what changed between them. Unlike a plain text diff, semantic JSON diff understands the structure of JSON: it compares objects by their keys regardless of order, so reordering keys in an object does not appear as a false change.

How to compare two JSON objects

1. Paste the original JSON in the left (Original) pane.
2. Paste the modified JSON in the right (Modified) pane.
3. Click Compare. Changes appear colour-coded: green for added, red for removed, amber for changed values.
4. Switch to Text diff mode for a line-by-line view. Choose word or character granularity for fine-grained comparisons.

Semantic diff vs text diff — when to use each

Semantic diff is ideal when you care about data changes, not formatting. If two API responses differ only in key order or indentation, semantic diff correctly reports them as identical.

Text diff is useful when you want to see the exact characters that changed — for example, comparing two versions of a package.json to see which dependency version bumped.

Why this is safer than pasting into AI tools

When you diff API responses or config files, those files can contain secrets, tokens, and proprietary business logic. Pasting them into AI chatbots or server-based diff tools sends your data to third parties. This diff checker runs entirely in your browser — nothing is uploaded.