JSON Diff
Client-sideGenerate a unified diff of two JSON documents after pretty-printing. Ideal for reading line-level changes quickly.
Processed in your browser — data stays on your device
About JSON Diff
JSON Diff pretty-prints both sides, then produces a unified diff so you can scan added and removed lines the way you would in code review.
Use it when formatting differences matter visually, or when you want a classic +/- patch instead of a structural path report.
Features
Pretty-print first
Normalizes formatting so whitespace-only noise is reduced.
Unified diff output
Familiar --- / +++ headers with - and + line markers.
Dual file upload
Drop left and right JSON files to compare quickly.
Copy the patch
Export the diff for tickets, chats, or pull request comments.
How it works
Provide two JSON inputs
Paste left and right JSON documents.
Generate the diff
Both sides are pretty-printed, then compared line by line into a unified diff.
Copy the patch
Copy or download the diff output for code review workflows.
Example walkthroughs
Nested change
The pretty-printed age line changes and appears with +/- markers.
{"user":{"name":"Ada","age":36}}Array change
Array item edits show up as replaced lines in the unified diff.
["alpha","beta"]
Use cases
Visual code-review style checks
Share a patch-like view of JSON changes with teammates.
Docs sample updates
See exactly which lines changed between documentation examples.
Quick before/after snapshots
Diff two exported payloads from staging and production.
Frequently asked questions
Why pretty-print before diffing?
Pretty-printing normalizes formatting so differences reflect structure and values rather than whitespace noise.
When should I use Compare instead?
Use JSON Compare for path-level structural reports. Use Diff when you want a classic unified patch view.
Is processing private?
Yes. Diffing runs only in your browser.
Related tools
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JSON Validator
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JSON Viewer
Explore JSON as an interactive tree with paths, types, and expandable nodes — all processed locally in your browser.
JSON Compare
Compare two JSON documents structurally. Find added, removed, changed, and type-changed paths — privately in your browser.
JSON Escape
Escape text into a JSON string literal, or unescape a JSON string back to raw text — instantly and offline.