Two useful views of the same change
Formatted markup re-indents both sides the same way and then diffs them, so you see the added featured class and the changed link target in the example alongside the copy edits. It's what you want when reviewing template or email-HTML changes.
Visible text only strips the tags and compares what a visitor reads: the price went from $9 to $12, the project limit rose, a feature was added and the button now says "14-day". Use it to check copy changes on a landing page or to compare two saved versions of an article.
Comparing structured data rather than pages? XML compare is stricter and keeps namespaces.
Questions
Can I compare just the visible text of two web pages?
Yes. Choose "Visible text only": scripts, styles and tags are stripped and each block element becomes a line, so you compare what a reader sees. Choose "Formatted markup" to compare the HTML itself.
Can I paste a URL?
No. Browsers block one site from reading another site's pages, and fetching them on a server would mean sending your data through us. Open the page, use View Source (Ctrl+U / Cmd+Option+U), copy and paste it here.
Does it handle broken HTML?
Yes. HTML is parsed the way browsers do, which repairs unclosed tags, so the comparison reflects how the page would actually render.