Compare two texts side by side and see additions, deletions, and word-level changes highlighted.
A diff (difference) checker compares two pieces of text — usually two versions of the same file — and shows what changed. Lines added in the modified version are shown in green; lines removed are shown in red. With word-level highlighting enabled, character-level changes inside changed lines are highlighted too.
This tool uses the Myers diff algorithm via the jsdiff library — the same algorithm used by Git for its diff and merge engines.
No. Comparison runs entirely in your browser; nothing is sent to any server.
Paste your original text into the left panel and the modified version into the right, then click Compare — additions appear in green and deletions in red, with word-level highlighting available for finer detail. Toggle "Ignore case" or "Ignore whitespace" first if you only want to see meaningful content changes.
A diff tool earns its place any time "what actually changed" isn't obvious just from looking at two versions side by side. Developers without git installed, or working with a file that isn't in version control at all, paste two versions of a script or config in here to see exactly which lines moved, since scrolling between two open tabs and comparing by eye misses subtle changes reliably. Writers use word-level diffing to review an editor's changes to a draft, distinguishing a meaningful rewrite from a minor punctuation fix without rereading the entire piece line by line. Comparing two environment configuration files — say, staging versus production — is a fast way to catch a setting that was changed in one place and forgotten in the other, a common source of "it works on my machine" bugs. It's also useful for a lower-stakes but common task: checking whether two paragraphs of text are genuinely different or just reformatted copies of the same content, which comes up when comparing submitted work or checking for accidental duplication across documents. Word-level highlighting specifically helps when only a few words changed inside an otherwise identical paragraph, making that change easy to spot instead of buried in a wall of unchanged text.
Want more detail? Read How to Use Text Diff Checker: Practical Guide and Best Practices.