Paste two versions of any text and text.compare highlights every difference: whole lines that were added or removed, the exact words that changed inside a line, and blocks that were moved rather than rewritten.
It works for code, contracts, essays, configuration files and logs, and it opens Word, Excel, PDF and image files too. Everything happens in your browser, so private documents stay on your device.
Not to compare it. The comparison runs entirely in your browser, and the text you paste and the files you open are never sent to a server for that. There are no ads. The site counts visits with Google Analytics, which sees which page you opened, and keeps its own anonymous tally of what kind of comparisons are made (for example “a Word file, about 500 lines”), but neither ever sees the text you compare. If you copy a share link, the text is packed into the link itself, in the part after the # that is never sent to a server or to analytics. Your history and saves stay in your browser unless you sign in. If you do, they are uploaded to your account, but only after they are encrypted in your browser with a passphrase only you know, so nobody else can read them. The site stores your email address and that encrypted data, and can see how much you have saved but not what it says.
Yes, with no account, no limits and no paid tier. The code is open source under the GNU AGPL-3.0 license, so anyone can host their own copy.
When a block of lines appears in both versions but in a different place, it is shown in violet with a tag saying where it moved to, instead of a red deletion and a separate green addition. Click the tag to jump to the other copy.
Yes. Options can ignore upper and lower case, spaces at line ends, all whitespace, or blank lines. You can also ignore anything matching a pattern, with ready-made ones for dates and times, GUIDs, hex values and numbers.