Diff Checker

No — the comparison runs entirely in your browser. Neither file is sent to a server.

Side-by-side shows both versions in two columns, aligned line by line — good for spotting exactly what changed on each side. Unified view shows a single column with +/- markers, closer to what you'd see in a git diff or patch file.

For lines that were modified (not purely added or removed), it highlights exactly which words changed within the line, rather than just marking the whole line as different.

Yes — use the "Upload file" button on either panel to load a file's contents in, then edit or compare as normal.

It works on any plain text — code in any language, config files, JSON, markdown, prose. It's a text diff, not a language-aware one, so it won't understand code structure, just line and word differences.