Diff Checker
Compare two texts and instantly see every difference. Runs 100% in your browser — your data never leaves your device.
Compare two text documents, code snippets, JSON files, or configuration files side-by-side with real-time visual syntax highlighting. Detect character-level, word-level, and line-level changes instantly in your browser.
Paste your original source code, configuration file, or base text into the left pane, or load directly from your clipboard.
Insert the modified or revised content into the right pane. The comparison engine analyzes differences dynamically.
Instantly examine color-coded additions (green) and deletions (red). Switch between line, word, or character precision modes.
Toggle between dual side-by-side panels or an inline unified git-style diff view depending on your review preference.
Drill down into exact character-level and word-level modifications within changed lines for precise code auditing.
Comparisons execute entirely in your local browser memory. Zero proprietary code or confidential data is transmitted to external servers.
Powered by an optimized Myers difference algorithm capable of comparing thousands of lines in milliseconds.
No. Sendly's Diff Checker processes all text comparisons entirely in client-side JavaScript within your browser. Nothing is ever sent to or stored on our servers.
Yes. You can paste large scripts or JSON documents. For optimal readability, we recommend using Sendly's JSON Formatter first to pretty-print, then running the diff comparison.
Sendly Diff supports Line Diff (standard line-by-line changes), Word Diff (ideal for prose and editorial copy), and Character Diff (crucial for minor typo and syntax debugging).
Yes. Simply click the Swap button in the toolbar to reverse original and modified panels instantly without re-copying.