Diff Checker - Compare Two Text Snippets Side by Side

Paste the original text on the left and the changed text on the right. The differences are highlighted instantly — additions in green, removals in red — using a line-level longest-common-subsequence algorithm so matching lines stay aligned even when blocks move around.

Split view shows the two snippets in parallel columns, which is the easiest way to read prose, contracts or translations. Unified view interleaves additions and removals in a single column with "+" and "-" prefixes — the same format Git uses, which is convenient for code review.

Yes. Toggle "Ignore whitespace" to collapse runs of spaces and tabs before comparing, which hides reformatting noise. Toggle "Ignore case" to lowercase both sides so "Apple" and "apple" are treated as identical. Both toggles can be combined.

The diff runs in your browser, so size is bounded by available memory rather than a fixed limit. Snippets up to a few hundred thousand characters compute instantly; very large files may take a moment, especially with both ignore-whitespace and ignore-case enabled.

Line-level diffs do not detect moves — when a block disappears from one place and reappears elsewhere, both edits are reported separately. That is the same behaviour as Git's default diff, and it keeps the algorithm fast and predictable.

No. Both snippets are diffed locally in your browser. Nothing is stored, nothing is transmitted and nothing is logged, so it is safe to compare confidential contracts, internal source code or unreleased copy.