Text Diff Tool
Compare two pieces of text and see what changed, line by line.
About Text Diff Tool
Text Diff Tool compares two pieces of text and shows what changed at the line level. It is for the everyday job of seeing the difference between two versions of anything — a contract draft and a redlined revision, a code snippet and its updated copy, the same paragraph from two contributors, a config file before and after a change.
Worked example: paste an original block of text on the left and the edited version on the right. Each line is classified as unchanged, added (highlighted green), or removed (highlighted red), and the result is shown as a unified diff in line order — the same '+' / '−' presentation Git's diff uses. A small counter shows the total number of added and removed lines.
Two practical notes. The diff is computed by a longest-common-subsequence algorithm at the line level — a change on a line shows as one removal plus one addition, not as a within-line word diff. For very large inputs (line counts multiplying to more than ~4 million pairwise comparisons), the diff is skipped to keep the page responsive — trim one or both sides to bring it back. The tool is not language-aware, so it treats code and prose alike — fine for everyday compare-two-versions work, but for serious code review you may prefer a tool that understands syntax (your IDE's diff or a PR view in GitHub).
All comparison runs in your browser. Drafts and unreleased text are never uploaded.