The majority of popup blockers only block popups that websites and services try to spawn automatically when they load. There are certain browser events that can spawn popups as well, and those are usually not blocked by default.
A very common option is to display a new browser window when you click on a link in the browser. There are others, like double-clicking on links or clicking on a submit button.
When you look at how Firefox handles popups, you will notice that it blocks popups automatically. You find the setting in the Options under Content. Here you can also add exceptions, that is websites that you want to allow popups to be launched on.
Websites and domains that you add here are allowed to display popups. A simple example where this may be appropriate is if you are using WordPress to publish articles. WordPress launches a new window when you click on the upload files button on the add media page. If you disable popups, that window is not displayed preventing you from doing so.
This is not an issue if you are running Firefox with default settings as it is an on-click popup event that is permitted automatically.
What many Firefox users do not know is that you can remove some or all of the exceptions that the browser makes in regards to popups.
Here is the list of events that will spawn popup windows in Firefox even if the popup blocker is enabled:
- change, click, dblclick, mouseup, reset, submit, touchend
Disabling all popups in Firefox
- Type about:config in the browser's address bar and hit the enter key.
- First time users need to confirm that they be careful on the next page.
- Type or paste dom.popup_allowed_events into the search field.
- The value of the preference highlights all events that are allowed to spawn popups.
- Double-click the preference and remove some or all of the items here. You can also add some if you want to do so.
The changes are active immediately in the web browser.
If you select enable, the domain will be added to the whitelist in the Firefox options.