Paste two versions of a text and see exactly what changed: line by line, word by word, entirely in your browser.
How it works
The tool lines the two texts up on the longest run of lines they share, the same technique developer diff tools use. Identical lines stay plain. Changed lines are shown as amber pairs with the differing words marked inline. Additions are green and removals red, each with its own line number per side.
Everything runs in your browser. Your texts are never uploaded, and there is no signup. The tool compares the two texts you paste. It is not a web plagiarism scan.
Frequently asked questions
How does the text compare tool work?
Paste your original text on the left and the changed version on the right, then click Compare. The two texts are lined up line by line. Lines that were changed, added, or removed are color-coded. Inside changed lines, the exact words that differ are highlighted too.
What do the colors mean?
Amber rows were changed. The line exists in both versions but differs, and the differing words are marked inline. Green rows were added in the new text. Red rows were removed from the original. Uncolored rows are identical.
Does it detect moved text?
Not as a move. The comparison finds the longest run of lines the two texts share, so a block that moved shows as removed in one place and added in the other. Developer diff tools present moves the same way. Reordered words inside a line are marked as changed words.
Is this a plagiarism checker?
No. It compares exactly the two texts you paste. Nothing is checked against the web. For a similarity score between two texts, our Text Similarity Checker gives a percentage. For web-scale plagiarism detection you need a crawling service.
How large can the texts be?
Thousands of lines is fine. Identical beginnings and endings are skipped at once, and only the differing middle is compared in depth. For very large texts that are completely different, the tool falls back to showing one removed block and one added block rather than freezing your browser.
Are line breaks and spaces significant?
Yes. Lines are compared exactly as written, including spacing, because in code, CSV data, and legal text those differences matter. If you only care about wording, normalize the texts first, for example with our Case Converter.
Can I compare two versions of a document?
Yes. That is the main use. Paste the old draft on the left and the new one on the right to see every edit at a glance. It works for articles, contracts, code, and data files, as long as you paste plain text rather than a formatted file.
Is my text uploaded anywhere?
No. The comparison runs entirely in your browser. Nothing is sent to a server and there is no signup. Your latest texts are remembered only in your own browser.