JSON Diff Checker — Compare Two JSON Files Online
Paste or upload two JSON files and instantly see every added, removed, or changed key and value. Free, private, and no signup.
Open the JSON diff toolA JSON diff answers a simple question that plain-text tools get wrong: what actually changed between two JSON files? Because the same data can be written with different key order, indentation, or minification, two files that hold identical data can look completely different as raw text. This tool computes a line-level diff with JSON syntax highlighting so real changes stand out.
Drop your original JSON on the left and the updated version on the right — or paste them directly. Every changed line is colour-coded: removed lines in red, added lines in green, with the specific characters that changed highlighted inside each line. It runs entirely on demand; your files are processed to compute the diff and are never stored.
For the cleanest result, pretty-print (format) both files with the same indentation first, and sort keys if order does not matter. The in-depth guide below covers exactly how.
How it works
Add both JSON files
Paste or upload your original and modified JSON into the two panels. Formatting the files the same way first gives the clearest diff.
Compare
Click Find Differences. The tool runs a line-level diff and highlights every changed key and value with JSON syntax colouring.
Review and share
Switch between side-by-side and inline views, use word or character precision for fine changes, and share a link to the result if you need to.
Frequently asked questions
Does this compare JSON as data or as text?
It computes a line-level text diff with JSON syntax highlighting. That covers the vast majority of real comparisons. For a fully structural (order-independent) comparison, format and sort both files first — the guide below explains how.
Why does the whole file show as changed?
Usually because one file is minified or indented differently. Pretty-print both files with the same settings, then compare again and only the genuinely changed lines will be highlighted.
Are my JSON files uploaded or stored?
Files are sent to the server only to compute the diff. They are processed in memory and are not stored or logged after the result is returned.
Want the full walkthrough?
Read the guide: How to Compare Two JSON Files Online