Diff Text

This is a line-based diff: it compares two blocks of text line by line using a longest common subsequence algorithm and highlights which lines were added, removed, or unchanged. It works well for comparing whole lines, such as config files, log entries, or short drafts, but it does not highlight individual word changes within a line the way some code editors do.

Writers comparing two drafts of an email or document, developers checking what changed between two versions of a config file, and anyone reviewing a before and after copy of notes, quotes, or pasted text to spot what was edited.

Common cases include comparing two drafts of the same email, checking a config file before and after a change, reviewing edits a colleague made to shared notes, or spotting what changed between two versions of a pasted API response.

No. This version compares full lines only, so a single changed word marks the entire line as different rather than highlighting just that word.

Very large pasted text may slow the tab, since the whole diff table is held in memory. Split large files into smaller sections if the comparison feels sluggish.

Yes. Both text boxes are compared entirely in your browser and are never uploaded.

No. The tool does not store previous diffs, so refreshing the page or leaving the tab clears both text boxes.