JSON Diff

JSON diff is for the specific situation where two objects are almost identical and you need to know the exact delta. Paste one in the left panel, the other in the right, and the differences surface with colour: green for keys that exist only in the right, red for keys that exist only in the left, yellow for keys that exist in both but whose values changed. Nested objects recurse — the comparison drills down through every level rather than treating the whole sub-object as a single changed value. This is the thing that matters when you're comparing API responses that differ by one field three levels deep.

Array comparison deserves a mention

Arrays compare by position, not by value identity. If you have an array of objects and the order changed, the tool will flag almost every element as modified even if all the data is the same — because index 0 in the left no longer matches index 0 in the right. This is correct behaviour for positional comparison, but if you care about set equality regardless of order, you'll want to sort both arrays by a stable key before diffing. Something like sorting by an id field in a text editor takes ten seconds and eliminates the false positives. The tool shows you what's structurally different; understanding whether that matters in your context is still on you.