Quo Vadis?

is a Firefox add-on that reveals what a shortened URL is hiding. It shows you where you would go if you clicked on an obscure or cryptic link; without clicking it. It has been available since 2012. Version 2.0.7 was released in January 2022.

Motivation

Shortened URLs such as ow.ly/8Pqgo or bit.ly/3yuZeRo are not transparent: you cannot see where they lead. Moreover, many shortened URLs do not lead directly to their final destination but use even less transparent detours. So I made 'Quo Vadis?'.

Quo Vadis? shows each step in the chain of redirects: where the found link redirects to, where the redirected link redirects to, and so on, up to and including the final page. It can handle all HTTP- and HTML-redirects.

Examples

The result of Quo Vadis? looks like this:

Example 1 Example 2

Quo Vadis? investigates the selected URL and reports the progress real-time. A small temporary pop-up shows every link in the chain of URL redirects. The bottom URL is the final URL, where the selected URL would take you, eventually. Every URL in the list is clickable, right-clickable, and scrollable.

These examples illustrate a few things:

  1. Just because a URL starts with HTTPS and ends with HTTPS, doesn't mean it uses HTTPS the whole way.
  2. Redirection URLs can be very long. That's why the list of URLs scrolls horizontally, and tooltips show the full URL as well.
  3. Most 'affiliate' links use complicated codes in their URL parameters, that somehow represent you. (But how?)

Value

When will this help you? If you are curious. If you don't want to blindly click on an obscure link. If you want to see if your internet traffic is conducted completely over secure connections. If you want to discover all intermediaries that collect statistics about your click behaviour. Or all of the above.

Usage

Add this add-on to your browser via addons.mozilla.org.

In Firefox, select 'Quo Vadis?' from the context menu of a link. The add-on will then display a list, with the URL you encountered, the URL being redirected to, and so on, up to the last URL. You can copy any URL if you want. Of course you can also click on any of the listed URLs (for example the last one). When the last URL does not produce an error (200 OK), it will turn green. If a URL returns an error (such as 404 Not Found), it will turn orange. A circular referral turns red.

The add-on relies entirely on the browser's internal capabilities. No external resources are used.

Conditions

The 'Quo Vadis?' add-on is free of charge. It nevertheless respects your privacy.
The source code is available under the 2-Clause BSD License.