Compare JSON

Curator's notes

A semantic JSON diff tool that understands structure, not just text. Detect value changes, type mismatches, and missing properties with full key-path context.

Visitors ask

Is my JSON data sent to a server?

No — unless you explicitly use the Share feature. All JSON parsing and comparison happens entirely in your browser using JavaScript. Your data never leaves your device and is not collected, transmitted, or stored. The optional Share feature on the result page uploads the compared content to their share server to generate a link, stored only until the expiration you choose.

How large a JSON file can this tool handle?

This tool uses efficient recursive algorithms with optimized memory usage. It handles JSON files with tens of thousands of keys and deeply nested structures, typically completing comparisons in under a second.

What array comparison modes are available?

Three modes are available: 'By Index' compares elements at the same array position, 'LCS' (Longest Common Subsequence) intelligently detects insertions and deletions while preserving order, and 'Unordered' treats arrays as sets, ignoring element order entirely.

Does this tool detect type changes?

Yes. The comparator is type-aware and distinguishes between different JSON data types, such as 42 (number) versus "42" (string), true (boolean) versus "true" (string), and null versus "null". Type mismatches are reported separately from value changes.