Paste two versions of a text or config file to see every added and removed line, with counts and an export of just the changes.
Runs in your browser — nothing is uploaded
Comparison is line by line, and line endings are normalised, so Windows and Unix files compare as equal. Changes inside a line are shown as the whole line removed and added.
A diff shows what changed between two versions of a text. Reviewers use it to read a pull request, operators use it to check a configuration before a deploy, and writers use it to see what an editor actually changed. Comparing line by line keeps the output readable for files where most lines stay the same.
The checker finds the longest sequence of lines the two versions share, then marks everything else as removed from the original or added in the changed text. Lines are compared exactly, so trailing spaces and letter case count as changes, while Windows and Unix line endings are treated as equal.
Long inputs are limited to 1,500 lines per side so the comparison finishes instantly in the browser. For a full repository history, use your version control system; for a quick review of two pasted versions, this page is enough.
Diff tools compare the exact characters, so a trailing space, a tab instead of spaces, or different capitalisation makes two lines different. That is often the real cause of a noisy diff in code and YAML, where indentation matters.
It uses a longest common subsequence: the algorithm finds the largest set of lines that appear in the same order in both texts, and treats the rest as additions or removals. A moved block therefore shows up as a removal in one place and an addition in another.
Each side can have up to 1,500 lines here. The comparison table grows with the product of the two line counts, so very large files would slow the page. Compare large files with diff, git diff or a desktop editor.
No. Windows CRLF and Unix LF endings are normalised before comparison, so copying a file between operating systems does not mark every line as changed. A missing final newline is also ignored.
Yes. The export below the summary lists the removed lines with a minus sign and the added lines with a plus sign, similar to a unified diff without the context lines. Paste it into a ticket or chat to show exactly what changed.
No. The comparison runs in your browser, so source code, contracts and configuration files you paste never leave your machine.