What is a Diff Checker?
A diff checker takes two pieces of text and highlights exactly what was added, removed, or kept the same. It is the same idea used by
git diff, code review tools, and document-comparison utilities — adapted to plain text so you can compare anything from log lines to configuration
files to article drafts.
What this tool does
- Three granularities — compare by lines (for code), words (for prose), or individual characters.
- Ignore whitespace — focus on real changes when only indentation moved.
- Ignore case — useful when the only difference is capitalisation.
- Patch output — copy a unified diff that you can paste into a code review or a
git applysession. - Counts — see exactly how many lines or tokens were added and removed.
Tips
- Use the Swap button to flip which side is "original" without retyping.
- For long files, lines granularity is fastest and easiest to skim.
- For paragraphs, switch to words for prose-style highlighting.
Everything runs in your browser — neither file ever leaves your machine, so the diff is safe to use on sensitive data.