JSON Compare Online

What a diff line means

Both panes are parsed as JSON. Object keys are matched by name, so {"b":1,"a":2} against {"a":2,"b":1} prints No structural differences found. A key only on the right is a plus line with the right-hand value. A key only on the left is a minus line with the left-hand value. A key on both sides whose values differ is a tilde, the left value, =>, and the right value. The sample is ~ price: 10 => 12. Nested objects use a dotted path when the key is an identifier. price under offer is offer.price. A key that is not an identifier, such as a.b as one key, is shown as $["a.b"].

Arrays are compared by index unless Ignore array order is on. [1, 2] against [2, 1] is ~ ids[0]: 1 => 2 and ~ ids[1]: 2 => 1 when the array sits on ids. An added index is a plus. A missing property is not null. Adding "a": null is + a: null. Removing a key whose value was null is - a: null. Changing an object to an array is one tilde at that path, {} => []. A number against the same digits in quotes is a tilde, 1 => "1". The root path, when the two top-level values differ and are not both containers of the same kind, is $. Identical values, including two empty objects, produce No structural differences found.

Ignore array order and the two panes

Ignore array order starts unchecked and updates the diff as soon as you toggle it. Checked, an array is compared as a multiset of its items, nested objects included, and duplicate counts stay. [1, 1, 2] against [2, 1, 1] is not a difference. [1, 1, 2] against [2, 1] is one tilde at the array path, ~ ids: [1,1,2] => [2,1], rather than a set of index lines that pretend the items lined up. Children of that array are not listed separately once the array itself is reported. Object key order is ignored either way. The checkbox does not sort your input. It only changes the comparison.

There is no button between the panes and the diff. Clearing one pane, or leaving it as spaces, replaces the diff with Provide JSON in both panes to compare. Invalid JSON replaces it with Invalid JSON in one or both panes. Validate and try again. and the parser message. A pane longer than 1,000,000 characters uses that same error line and the limit sentence. Load sample writes the price pair and shows the one tilde as soon as both sides are set. Reset clears both boxes. The copied text is the diff, including the no-difference sentence when that is what the panes produced. The download file is json-compare.txt.

When a property path is the review you want

Use the panes when the identity of a change is the key or the index, not the character column where it happened to sit. An API response with an added field, a config object with a changed number, or two fixtures that should match except for one path all fit. A line-oriented edit, such as a README or a pair of env files, is easier in the text diff viewer, which marks rows rather than property paths. Pretty-printing either side first is the JSON formatter. This page does not indent the inputs.

Turning the objects into rows is JSON to CSV. The request guide is about reading a browser call as code, which is a separate step from diffing two bodies you already captured. This page does not fetch either document. Paste both. It also does not decide which side is newer. The left pane is the left value and the right pane is the right value, and the arrows point left to right.

Duplicates, null, and numbers that are strings

Duplicate counts are part of the unordered comparison. Dropping one of two identical ids is a change even when Ignore array order is on, and the line shows both arrays. Order-sensitive mode would instead report index changes that may be only a shuffle. Pick the mode that matches the contract. A missing key and a key set to null stay different, including when the null is nested. An empty array and a missing array stay different. An empty object and an empty array stay different.

JSON numbers are JavaScript numbers. An integer wider than the safe range can already have been rounded by the time the diff runs, so two ids that differed only past that range can look equal. Keep those ids in strings. Two strings are compared exactly, so a trailing space is a change. Duplicate keys in one object collapse when the pane is parsed, and the last value is the one that is compared. Comments and trailing commas are invalid and clear the diff into the error sentence. The page will not repair them. Split a huge document and compare the section you care about if the browser slows down. The limit is per pane.

Comparison rules

Object keys match by name. + was added on the right, - was only on the left, ~ changed. Paths are dotted for identifier keys, bracketed for other keys, and indexed for arrays. The root is $ when a top-level scalar or a container type changes.

Arrays compare by index until Ignore array order is on. That mode keeps duplicate counts and reports a changed array at the array path. Missing is not null. Each pane allows 1,000,000 characters. The diff updates as you type. Copy and download are the diff text.

Common problems

If a shuffle of the same items filled the diff, Ignore array order is off. Turn it on. If a duplicate disappeared and the diff stayed quiet, the counts really match. [1, 1, 2] against [2, 1] does not.

If both panes look like JSON and the line says Invalid JSON, look for a trailing comma, a comment, or single quotes. If a huge integer matched unexpectedly, it was parsed as a JavaScript number. Quote it.

Frequently asked questions

About this tool

Maintained by Toolbench. For large or deeply nested files, split the input into smaller batches and verify representative results before using them in an import or application. Report reproducible problems through Contact.