JSON Diff

How is this different from the text diff checker?

It compares structure, not lines. Reformatting a file, changing indentation, or reordering the keys of an object produces zero differences here — all of which would light up a line-based diff. If you want to know what changed in the data rather than in the file, this is the tool; for prose or code, use the diff checker.

Are object keys order-sensitive?

No. JSON objects are unordered by definition, so {"a":1,"b":2} and {"b":2,"a":1} are identical and reported as such.

Are arrays order-sensitive?

Yes. Arrays are compared by index, so moving an element counts as a change at both positions. That is the correct reading of JSON semantics — order is meaningful in an array — but it does mean a reordered list produces a noisy diff rather than a "moved" note.

What do the four change kinds mean?

added — the key exists only on the right. removed — only on the left. changed — present on both with different values of the same type. type-changed — present on both but the type differs, such as the string "5" becoming the number 5. That last one is called out separately because it is a common and easily missed source of bugs.

How do I read the paths?

As a JSONPath-style trail from the root: $ is the document itself, $.user.email is a nested key, and $.user.emails[2].label indexes into an array. You can paste the path into most JSON query tools.

Why did it report an error instead of a diff?

Because one side is not valid JSON. The tool tells you which side failed rather than guessing — the most common causes are trailing commas, single quotes instead of double, and unquoted keys, none of which are legal JSON even though JavaScript accepts them.

Does it detect a renamed key?

No. A rename appears as one removal and one addition, because there is no reliable way to tell a rename from an unrelated pair of changes without guessing at intent.

Does key order or whitespace affect the result at all?

Only inside strings. Whitespace between tokens is insignificant to JSON and is ignored; whitespace within a string value is part of that value and will be reported.

Is my data uploaded?

No. Both documents are parsed and compared in your browser.