How to compare two texts
Paste the original text into box A and the changed text into box B, then press “Compare texts”. Words added in B show in green; words removed from A show in red with a strikethrough. Unchanged words stay plain. A summary line tells you how many words were added, removed, and left unchanged, plus a similarity percentage. Nothing is uploaded.
How the comparison works
The tool compares word by word, not character by character. That is the right granularity for writing: a changed word shows as one change, instead of a spray of changed letters. Punctuation stays attached to its word, and spacing is preserved, so the output still reads like your text. For very long texts (over about 1,500 words per side) it switches to a line-by-line comparison, which is faster and easier to scan.
Common uses
Checking an edit: paste your draft and the edited version to see exactly what a colleague or an AI tool changed. Proofreading a revision: compare a contract before and after negotiation to catch altered clauses. Spotting plagiarism-style copying: compare a suspicious passage against your original. Reviewing translations: compare two drafts of the same text to see which wording survived.
Reading the similarity score
Similarity is a rough guide, not a verdict. Two texts that differ by a few words score above 95%. A rewrite that keeps the meaning but changes the wording can score 60% or lower while saying the same thing. Use the score to spot how much changed, and read the highlighted words to judge whether the change matters.
Limits to know
The tool compares text, not meaning. It cannot tell you that “big” and “large” mean the same thing — it will show them as a deletion plus an addition. It also works on plain text only: formatting, images, and tracked changes from a word processor are not compared — paste the words themselves. For texts over 1,500 lines, compare them in smaller chunks.