Compare Two Texts

No. Both texts are compared entirely on your device, and nothing is sent to a server - there’s no upload step at all, unlike a tool that makes you choose a file first. Turn off your Wi-Fi after the page loads and it still works. This page loads 3KB of JavaScript, gzipped - about what your browser’s network tab will show for this page’s own scripts.

Comparing text is almost always a copy-paste task (two versions of a paragraph, two config snippets, two emails) rather than a compare-two-files task - a file-upload step would add friction for the common case. This tool skips it entirely: paste into both boxes and the comparison is already there, with no “Compare” button, no ads, and no account.

Yes. The comparison is order-sensitive at both the line and word level, the same way a code diff tool works - “the cat sat” and “sat the cat” are reported as a real change, not treated as a match just because they share the same words. This also means a paragraph that got reordered will show as removed-and-re-added lines rather than “unchanged,” which is the honest read.

Yes - code is just text with meaningful line breaks and indentation, and this tool compares both. Leave “Ignore whitespace” off to catch indentation-only changes (the kind that break some languages), or turn it on to compare logic while ignoring formatting differences.

The line-by-line comparison uses an algorithm whose work grows with both texts’ line counts multiplied together, so an extremely large pair of texts (each in the low thousands of lines or more) may be refused with a message asking for shorter input, rather than freezing the tab. Ordinary pastes - anything from a sentence to a long document - have no practical limit.

Both only change which lines COUNT as different - the highlighted text always shows exactly what you pasted, unchanged. “Ignore whitespace” treats two lines as equal if they only differ by leading, trailing, or repeated spacing (so re-indented code doesn’t show as changed). “Ignore case” treats “Hello” and “hello” as equal.

A removed-and-inserted line pair is only shown as one “changed” line (with the specific words that differ underlined) when the two lines are similar enough that highlighting a word-level difference is more useful than showing them as unrelated - the same threshold ../pure/csvDiff.mjs’s cell-level diff uses for CSV rows. Two lines that share almost nothing in common are shown as a plain removed line and a plain added line instead.