Compare two texts and highlight added or removed lines.
Updated
| A | Original | B | Changed |
|---|---|---|---|
| 1 | function add(a, b) { | 1 | function add(a, b) { |
| 2 | + // sum the args | ||
| 2 | return a + b; | 3 | return a + b; |
| 3 | } | 4 | } |
| 4 | 5 | ||
| 6 | +console.log(add(2, 3)); | ||
| 5 | -console.log(add(1, 2)); |
Quick start
Paste both versions, see additions and deletions side-by-side with line numbers.
Drop the baseline version into the left textarea.
Drop the modified version into the right textarea.
Two-column view shows unchanged, added (green) and removed (red) lines with line numbers from each side.
In-depth guide
Compare two pieces of text line by line in a GitHub-style two-column view. Built for code review, config audits and prose-drafting — anywhere line-level granularity beats character-by-character.
nginx.conf from staging vs production.No. The diff is computed in your browser. Useful for diffing config files, prose drafts or code where you don't want to upload to a hosted service.
text-diff is line-level — each line is a unit of comparison. Use it for code, config, prose. string-diff goes character-by-character — better for short strings, version numbers, single sentences.
No, whitespace is significant — a changed indent or trailing space shows as a diff. Normalise inputs (trim trailing whitespace, convert tabs) first if you want to ignore those.
We split on \r?\n so the line endings themselves are stripped before comparison. Two files with the same lines but different endings will compare equal.
Each delete is +1 removed, each insert is +1 added, a paired delete-insert on the same row counts as both. Numbers are line counts, not character counts.
Not yet — output is a side-by-side view only. For patch-format output use the git diff or diff command from your terminal.
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