JSON Diff — Compare Two JSON Documents

Paste two JSON documents and see exactly what changed between them: which keys were added, which were removed, and which values moved. Comparison happens in your browser, so neither document is uploaded anywhere.

How the comparison works

Objects are compared key by key, so the order you happened to write the keys in never counts as a difference. Arrays are aligned with a longest-common-subsequence pass first, which means inserting one element at the front reports a single addition instead of renumbering every entry after it. When an element really was replaced, the old and new versions are paired up and compared field by field, so a single edited value inside an array reads as one change rather than a removal and an addition.

The result is drawn as a real side-by-side view: both documents are pretty-printed with line numbers, and blank filler lines are inserted so matching content stays level across the two panes. Removed lines are tinted on the left, added lines on the right, and a changed value is highlighted on both sides so you can read the old and new values at the same height. The two panes scroll together. Use Changes to fold long unchanged stretches down to a few lines of context — click a fold to open it — or All to show every line. The ↑ ↓ buttons (or the p and n keys) jump from one change to the next, and Copy report puts a path-addressed summary such as~ $.users[2].email on your clipboard as plain text.

Scroll back up and paste both documents — the comparison runs as you type.