Text Diff Checker
Paste two versions of a text and see exactly what changed — lines added in green, lines removed in red, and a clear count of each. Useful for drafts, contracts, code and anything with a before and after.
Compare two texts
The loaded example shows one edited line and one added line — try it.
The comparison will appear here — added lines in green, removed lines in red.
Just the differences
Green for added, red for removed, and the counts before the detail.
Line-by-line diff
The comparison engine matches lines between the two versions, so a moved or edited line is shown as a removal plus an addition, exactly like code review tools.
Change counts up top
Added, removed and unchanged line counts lead the result, giving you the size of the change before the detail.
Whitespace option
Tick “ignore spaces at line ends” and re-indented or trailing-space-only edits stop counting as changes.
About the text diff checker
When a document exists in two versions, the only question that matters is what changed — and reading both versions in full to find out is slow and unreliable. This checker compares the two texts line by line and presents just the differences: new lines in green, vanished lines in red, and unchanged lines in plain text for context.
The line-by-line approach is the same one programmers use in code reviews, and it suits most real documents: articles, essays, contracts, terms, configuration files, lists and lyrics. An edited line shows as the old line removed and the new line added, which keeps the display honest — the tool never guesses which words inside a line changed, it shows you both lines so you can see for yourself.
Practical limits are stated on the page: about 600 lines per side keeps the comparison instant, and the optional spaces setting ignores leading and trailing whitespace for documents that were re-indented. Both texts are processed entirely in your browser tab — nothing is uploaded, saved or shared, which makes the tool safe for unpublished and confidential material.
Frequently asked questions
How the comparison works and what it cannot do, answered plainly.
How does the comparison work?
Line by line. Lines that exist only in the second text are marked as added, lines that exist only in the first are marked as removed, and matching lines are shown as unchanged context.
Why does an edited line show as one removal and one addition?
Because the line itself changed — the old version is gone and a new one exists. Showing both lines in full is more honest than guessing which words inside the line were edited.
What does “ignore spaces” do?
It compares lines without their leading and trailing spaces, so a line that was only re-indented counts as unchanged. The displayed lines still show their original spacing.
How much text can I compare?
Up to about 600 lines in each box. That covers most documents and files people compare; very large files are better handled by a desktop diff tool.
Are the two texts identical a valid result?
Yes — if nothing differs, the tool says so plainly and every line is counted as unchanged. That confirmation is often the whole point of the check.
Is my text uploaded?
No. The comparison runs in your browser. Drafts, contracts and other private texts never leave your device.