About Redline Pad
A small tool for a small job: two versions of a clause, compared right now, without saving a file or sending anything anywhere.
What it is
Redline Pad compares two versions of a piece of text and shows you what changed, marked the way a lawyer expects to see it: insertions underlined, deletions struck through in place rather than hidden or moved to a margin. You paste the original on one side and the revised version on the other, and the redline appears as you type.
It is built for the job that comes up several times a day and does not deserve a document-comparison workflow — a clause pasted out of an email, a paragraph somebody rewrote overnight, two versions of a definition that look identical until you read them twice. You want to know what moved, and you want to know now.
That is a literal statement rather than a reassuring one. The page is served with a Content-Security-Policy that forbids it from contacting any other origin, which you can read for yourself in your browser's developer tools in about thirty seconds. It is the one claim this tool makes that matters, so it is the one claim it makes checkable.
What it is not
It is not a document-comparison platform, and it will not become one. It does not open Word files, does not produce a DOCX with tracked changes, does not keep a history of what you compared, and has nothing to say about a two-hundred-page agreement with numbering and cross-references and a styles sheet somebody spent a week on.
Word's own Compare, Litera, Draftable and the rest are good at exactly those things, and they are the right tool when the job is a whole document, a file format, a round trip back into tracked changes, or anything a firm needs supported. If that is what you are doing, use one of those. This tool is for the clause you have in front of you now.
How it works
Both versions are turned into a plain internal representation — paragraphs, headings, lists, and marks like bold and italic — and compared word by word. The comparison itself is a Myers diff over words, with a pass that recognises when a paragraph was split or merged and a second pass that spots formatting that changed without the text changing.
Two rules constrain everything else. Your text is never rewritten: settings like Ignore spacing and Match case change a derived key used for the comparison, never the characters that get displayed or copied. And the same two inputs always produce the same redline, byte for byte, so a colleague running the same comparison sees the same thing you did.
Who made it
One person, in the open, because the tool I wanted did not exist in a form I was willing to paste a client's clause into. It is a small piece of software and it is meant to stay small.
If something is wrong, or the redline disagrees with what Word would have shown you, I would like to know. There is a feedback form, and it is the one place in the product that deliberately sends something you typed — the message you write in it, and nothing else. It is kept well away from the tool for that reason.
What it costs
Nothing, and there is no account to make. There is no paid tier waiting behind a limit, no trial that expires, and no upsell. If that changes, this page will say so before anything else does.
The site counts page views and a handful of anonymous events — that a comparison was run, and which copy format was used — through analytics served from this domain, with no cookies and nothing about your text. The privacy page lists every event by name.