Compare Two Texts and Find the Differences
Two versions side by side, every change marked.
The answer appears here as you type.
Guide: What changed between two versions2 min read
What changed between two versions
Paste the original text on top and the changed version underneath. The comparison appears as you type: added lines marked in green with a plus sign, removed lines in red with a minus, unchanged lines unmarked. The sign is in the text itself, so the difference stays clear to anyone who cannot tell the colours apart, and in the saved file.
It is for checking what someone changed in a contract, finding the line that moved in a config file, comparing two API responses, or two drafts of a text before publishing.
How the comparison is worked out
It uses Myers' algorithm, the one git uses. It looks for the fewest lines to remove and add to turn one text into the other — which is why a whole block that did not change shows as unchanged even with edits before and after it. With the options, extra spaces and differences in case stop counting, and “Show only what changed” folds long identical runs into a count.
Nothing is uploaded
Both texts are compared in this tab and never leave it, which matters when the content is a contract or private code. After comparing, you can count the words of one version or remove repeated lines from a list.
Frequently asked questions
How does the comparison work?
Line by line, with the same algorithm git uses (Myers). It finds the smallest set of lines to remove from the original and add to reach the changed text, so a block that did not change is shown as unchanged rather than removed and added again.
Can I ignore spacing or capital letters?
Yes. With “Ignore extra spaces”, lines that differ only in indentation or doubled spaces count as equal; with “Ignore upper and lower case”, so do lines that differ only in capitalisation. The lines are still shown as they were written.
Is it safe for contracts or source code?
The comparison runs entirely in this tab, so nothing you paste is uploaded or stored — which matters for contracts, private code and internal documents. The page works with the connection off.
Why is a changed line shown as removed and added?
Because the comparison is by line: a line with one word different is a different line. The removed version sits right above the added one, so the change reads at a glance. Words inside the line are not highlighted separately.
Can I save the result?
Yes. Copy or save it as a text file in the usual diff notation: a plus sign for an added line, a minus for a removed one, and two spaces for an unchanged one.