Diff viewer
Compare two blobs of text. Three granularities — lines, words, characters — produce a unified-diff (lines) or a GNU-wdiff-style inline view (words/chars). Everything runs in your browser; neither side leaves the page.
Mode
Line-by-line diff. Best for code, configs, anything where each line is a unit.
Left
The original side. Removed lines show in red.
Right
The changed side. Added lines show in green.