Text Diff Checker
Compare two blocks of text and instantly see every word that was added, removed, or changed.
Green highlights show text added in the second box; red strikethrough shows text removed from the first. Comparison runs entirely in your browser.
How the Text Diff Checker works
Paste your original text on the left and the changed version on the right. The tool highlights every word that was added (green) or removed (red strikethrough), while unchanged words are left as-is.
This makes it easy to spot exactly what changed between two drafts, contract revisions, or versions of an article without having to read both side by side line by line.
Frequently asked questions
How does the comparison decide what changed?
It uses a word-level longest common subsequence (LCS) algorithm — the same class of algorithm behind tools like 'git diff' — to find the smallest set of word insertions and deletions that turns the original text into the changed text.
Does it compare character by character or word by word?
Word by word (with whitespace preserved), which produces more readable results for prose and paragraphs than a character-level diff, where a single added letter can make an entire word look changed.
Can I compare two full documents?
Yes, though very long documents (many thousands of words) may compare more slowly, since the underlying algorithm's performance scales with the length of both texts.