About this tool
A plain text diff of two JSON files is noisy: reordering keys, changing indentation or reformatting shows up as hundreds of false changes. This tool first parses both documents, then (with Ignore key order on) recursively sorts object keys and re-serialises with consistent 2-space indentation before diffing, so you see only genuine semantic changes: keys that were added or removed, and values that changed. Arrays are compared in order. Invalid JSON is flagged with the parser's error message. Everything runs locally in your browser, so API payloads, secrets and config never leave your machine.
Frequently asked questions
Does it ignore the order of object keys?
Yes, when Ignore key order is on (the default). JSON objects are unordered by specification, so {"a":1,"b":2} and {"b":2,"a":1} are treated as identical. Turn the option off to diff the raw formatting as written.
How are arrays handled?
Arrays are ordered in JSON, so they are compared element by element in position. Inserting an element near the start will show the following elements as shifted.
Is my data uploaded?
No, parsing and diffing happen entirely in your browser. For non-JSON text use the Text Diff tool.