Text Compare: Find the Differences Between Two Texts
Compare two texts and see every change highlighted: removed lines, added lines, and the exact words edited inside each changed line. It works as a free diff checker for documents, code, and config, entirely in your browser with nothing uploaded.
How the text compare tool finds differences
Comparing two texts sounds simple until you try it by eye. The tool splits both texts into lines and finds the longest common subsequence: the largest set of lines that appear in both, in the same order. Everything outside that set is a change. Lines only in the original are deletions, and lines only in the new version are insertions. This is the same approach version-control systems use, based on Eugene Myers' diff algorithm, which finds the smallest edit that turns one text into the other. Then, for each line that was edited rather than added or removed, it runs a second comparison word by word, so a single changed figure in a long paragraph is highlighted on its own instead of the whole line lighting up.
Side by side or inline?
Side by side lines the two versions up in parallel columns, which is the easiest way to read edits to prose, contracts, or configuration. Inline shows a single column with removed lines marked "−" and added lines marked "+", the format you know from code review, and it fits narrow screens better. "Only changed lines" folds away long unchanged stretches and keeps three lines of context around each change, so a two-line edit in a 2,000-line file is easy to find.
Ignoring whitespace and case
Many differences are noise. Text copied out of a PDF or an email picks up stray spaces, and code reformatted by an editor changes indentation on every line. "Ignore whitespace" compares lines with that stripped out, so only real edits show. "Ignore case" does the same for capitalisation, useful when one version was run through a case converter.
Private by design
People compare contracts, offer letters, source code, and API responses: exactly the material you should not paste into a stranger's server. This diff checker runs entirely in your browser and never sends either text anywhere. Need something else? To find items missing from one list regardless of order, use compare two lists. To check structured data, tidy it first with the JSON formatter so both sides use the same layout before you diff them.
Frequently asked questions
How do I compare two texts for differences?
Paste the original text on the left and the changed version on the right. The differences are highlighted as you type: removed lines in red, added lines in green, and changed lines show exactly which words were edited. Switch between side-by-side and inline views with the buttons above.
Is this the same as a diff checker?
Yes. A diff checker and a text compare tool do the same job: they find the smallest set of line insertions and deletions that turns one text into the other, then highlight them. This one also highlights the changed words inside each edited line, which makes small edits in long paragraphs easy to spot.
Can it ignore whitespace and capitalisation?
Yes. "Ignore whitespace" treats lines that differ only in spaces or indentation as the same, which is useful for re-indented code or text pasted from different editors. "Ignore case" treats "Hello" and "hello" as identical.
Is my text uploaded when I compare it?
No. The comparison runs entirely in your browser, so contracts, code, and private drafts never leave your device. Most online diff checkers send both texts to their server; this one makes no network request with your text at all.
How do I compare two lists rather than two documents?
A diff respects order, so it reports a moved item as one deletion and one insertion. To find which items appear in one list but not the other, regardless of order, use the compare two lists tool instead.
Related reading
- How to Compare Two Lists and Find What's Missing
The formulas for Excel and Google Sheets, the invisible characters that break matches, and a paste-and-go alternative.