How to link PDF pages to a web address
Link to a web address from a PDF in PDF by Zaweba with a bookmark action, or with Pages > Page actions so a site opens when a page opens or closes.

There are two ways to link to a web address in PDF by Zaweba. A bookmark can be given an action that opens a web address, so clicking it in the Bookmarks panel takes the reader to the site. Or Pages > Page actions can open a web address when a particular page opens or closes. Pick whichever fits how you want readers to reach the link.
Linking out from a PDF is useful whenever a document points to something that lives online: the latest version of a manual, a booking page, a video that goes with a training handout, or a form to fill in on a website.
Using a bookmark
A bookmark normally takes you to a page, but it can do more. Its action can be a page, a web address, a file or a menu command.
Add a bookmark with Ctrl+B and give it a clear name, such as "Latest version online" or "Book a place". Then set its action to open a web address and enter the address. Rename it with F2 if you need to. Readers see it in the outline down the side of the document and click it when they want it.
This is the gentle option. The link is there, easy to find, and only used when the reader chooses to.
Using a page action
Pages > Page actions sets what happens when a page opens or closes. One of the choices is to open a web address. Others are to go to a page, or to move to the next, previous, first or last page.
Choose the page, choose whether the action happens on opening or closing it, and set it to open your address.
This is the firm option. The link opens without the reader clicking anything, so use it with care. It suits a kiosk or display PDF where the next step is always the website, or the last page of a document that hands over to an online form.
Links readers trust
Prefer bookmarks for ordinary documents. Most readers don't like a web page opening without warning, and some PDF readers ask permission first or block it.
Use full addresses and test them. Open the bookmark or turn to the page yourself and make sure the right site appears.
Name things honestly. A bookmark that says where it goes is far more likely to be used, and trusted, than a vague one.
Think about the document's life. A web address that works today may not in two years. For long-lived documents, link to a stable page you control.
Safety built in
Page actions in PDF by Zaweba are deliberately limited. Scripts in page actions are kept in the file but never run, and loops aren't allowed, so a page can't send a reader round in circles. When you receive PDFs from others, that's a sensible protection.
Other ways actions help
The same tools can make a PDF behave more like a presentation. Page actions can move to the next page automatically, and Pages > Page transitions adds effects and timed page turns in full screen. A bookmark that runs a menu command can put a common job, such as printing, right in the outline.
Both approaches are set up offline in PDF by Zaweba and stored in the PDF itself, so they work for readers using other PDF software too, within whatever limits their software sets.