Paste two versions of any text and see exactly what changed — line by line and word by word. Nothing is uploaded; it all runs in your browser.
Tip: your two texts are kept in this browser (localStorage) so they're still here when you come back. Nothing is sent anywhere.
Text Diff compares two blocks of text and shows you what changed between them. Lines that were added in the second version are marked in green with a +; lines that were removed are marked in red with a −; lines that stayed the same are shown plainly. When a line was edited rather than added or removed wholesale, the tool highlights the exact words that changed inside it, so you can spot a one-word edit in a long paragraph at a glance.
Treats Hello and hello as the same, so changes in capitalisation aren't flagged as differences. Useful when only the wording matters.
Ignores differences in spaces, tabs and blank runs (leading, trailing and repeated). Handy when one version was re-indented or re-wrapped but the actual words didn't change.
When a line was edited, this highlights the specific words that were added or removed within it, instead of just marking the whole line. Turn it off if you'd rather see clean whole-line changes.
The tool aligns the two texts using a longest-common-subsequence match on their lines — the same idea behind the diff command and version-control tools. It finds the largest set of lines that appear, in order, in both versions, then marks everything else as inserted or deleted. For edited lines it runs the same match again at the word level. All of this happens locally in your browser in a fraction of a second; your text never leaves your device and nothing is stored on a server.
Everything runs client-side. The two texts are saved only in your own browser's local storage so they survive a refresh, and you can wipe them any time with Clear. No uploads, no accounts, no tracking cookies.