Every PDF carries a small block of document information: title, author, subject, keywords, the creator application, the producer library, and the creation and modification dates. Many PDFs also hold a second, XML copy of the same data (XMP metadata). This editor reads all of it in your browser and shows it in a form you can change.
Edit any field and save a copy, or empty a field to remove it. Dates use your local time and have a Now button. If the file has an XMP block, the tool can remove it as well, because some readers such as Acrobat show the XMP values instead of the ones you just edited. The Remove all metadata option strips every field and the XMP block in one go, which is useful before you send a document outside your organisation.
What it doesn't touch: page content, bookmarks, links and form fields stay as they are. Metadata inside embedded images (such as camera EXIF data) is not changed; use an EXIF remover on images before you put them in a PDF.