Articles · Developer Tools
See what changed in text, files, or JSON
Two versions of a README, a policy, a config, or a JSON payload look identical until they are not. Scrolling both windows is how you miss a deleted line. A diff that marks added, removed, and unchanged with symbols as well as color is usable for color-blind readers and for copy-paste into a ticket. Keeping both sides in the browser means the draft never hits a public paste site.
Why this is worth doing in the browser
Character-level noise is optional; v1 focuses on line and word comparison with ignore-case, ignore-whitespace, and ignore-blank-line options. Text mode is two panels. File mode reads TXT, MD, JSON, CSV, XML, and YAML locally. JSON mode can parse both sides and report added properties, removed properties, changed values, and array differences instead of a wall of shifted braces. You can copy left to right or right to left for a simple fix—not a Git merge engine. Download the unified diff as plain text when you need an artifact. Large inputs are capped so the tab stays responsive.
How to use the tool
Paste or open files, choose line or word, pick side-by-side or unified, compare. For JSON, choose structural or text comparison. Copy a side or download the diff. Continue to the JSON Formatter or Data Converter when the next step is pretty-print or a format change.
- Start with line diff for documents; switch to word when a single sentence moved.
- Parse JSON before you trust a structural report; invalid JSON is explained without a stack trace.
- Use ignore options only when you know whitespace is noise.
- Copy a selected side; do not expect a three-way merge.
Privacy
Comparison runs in your browser. File contents and diff text are not uploaded to DevNestro and are not sent to analytics.
Need to prove a paragraph changed? Open the Diff Checker, compare locally, and download a plain-text diff if you need a record.