Diff Checker
Compare two blocks of text or code and see exactly what was added, removed and changed, line by line.
Works offlineDeveloper
Original
Changed
Paste two versions above to see what changed.
About the diff checker
Paste an original and a changed version to get a line-by-line diff with additions and removals marked, viewable either as two side-by-side panes or as a single unified list. Options let you ignore whitespace differences or case, and a summary counts how many lines were added, removed and left alone. Everything is computed locally.
This tool runs entirely in your browser. Nothing you type is uploaded, and it keeps working with no connection at all — including as an installed app.