An article is not finished when it is published. A theme update, a new plugin or work on a different article can change its headings, text or links without anyone intending it. This article describes a routine for noticing those changes and confirming whether the page is still correct.
The routine checks whether the content of an article has changed. It is not a security scan, which has a different purpose and method. Nor does comparing pages by itself improve search rankings.
Why check after publication
When experts review or comment on an article, readers rely on the text they see matching the text the experts read. If a heading is reworded or paragraphs are reordered, it becomes unclear which part a comment refers to. Noticing a change early gives the editor and the reviewer time to respond calmly.
What to compare
Compare only what readers read as the article: the title, the headings, the paragraphs and their order, and the text and destination of links in the body. Changes to share buttons, adverts or site-wide menus add review work without helping anyone decide whether the article is still right.
Fetch the page the way an ordinary reader does, without signing in and without relying on JavaScript, so that you compare the same HTML that readers and search engines receive. For how HTML headings work, see MDN on heading elements .
When a difference appears
First, check the article's edit history to see whether the change was intended. If it was not, restore the previous version and find the work that caused it. If it was, tell the reviewer or the experts who commented, and ask them to look again where needed.
In either case, record the date and time, who checked, and the reason for the decision. When the same article changes again, the earlier decision is then easy to find.
Accepting an intended revision
Once a revision is confirmed as intended, make that version the new basis for comparison. If the basis is never updated, the same difference is reported again and again. If it is updated without review, unintended changes slip through. The safest arrangement is for the person who completed the review to update the basis.