Cookie scanner
A cookie scanner is a tool that crawls a website's pages and lists the cookies, scripts and third-party services it finds, so the site owner knows what to put in the cookie banner and the cookie policy.A banner can only ask for consent to what the site owner knows about, and most sites load more than their owners think: a tag manager adds tags, a theme loads fonts, a plugin embeds a video. A scanner visits the pages and records what each one sets or loads, usually the cookies in Set-Cookie headers and in the browser, the domains of scripts, iframes and images, and sometimes local storage. A provider database then names each item, its purpose and its category.
Scanners differ in how they look. A scanner that runs a real browser sees cookies set by JavaScript; one that reads the HTML sees the tags and headers but has to infer what scripts would set. A useful scan also runs twice: before any consent, to check that nothing optional fires, and after accepting, to fill the cookie table. The cookie audit checklist covers the manual steps around it.
Cookiequiet's scanner crawls up to 10 pages on Free and 50 on Starter and Pro, reads scripts, iframes, stylesheets, beacons and Set-Cookie headers, and names what it finds from a database of about 80 providers; without its rendered-HTML option it does not run JavaScript, so cookies set purely by scripts are listed from that database rather than observed. The free cookie scanner checks 5 pages without an account.