Detect “Do Not Track” with JavaScript
Do Not Track is an excellent idea. The DNT website describes it best:
Do Not Track is a technology and policy proposal that enables users to opt out of tracking by websites they do not visit, including analytics services, advertising networks, and social platforms. At present few of these third parties offer a reliable tracking opt out, and tools for blocking them are neither user-friendly nor comprehensive. Much like the popular Do Not Call registry, Do Not Track provides users with a single, simple, persistent choice to opt out of third-party web tracking.
The preference is sent from the client to the server via a HTTP header but you can also get its value using JavaScript:
// "1" or "unspecified"
if(navigator.doNotTrack == 1) {
// Do (or don't do) stuff.
}
If you wanted to be extreme about honoring your user's preference, you could use that to lazyload (or not) advertising, analytics, or other utilities. Probably a bit extreme but it's there for you to use!
![CSS Gradients]()
With CSS border-radius, I showed you how CSS can bridge the gap between design and development by adding rounded corners to elements. CSS gradients are another step in that direction. Now that CSS gradients are supported in Internet Explorer 8+, Firefox, Safari, and Chrome...
![Responsive Images: The Ultimate Guide]()
Chances are that any Web designers using our Ghostlab browser testing app, which allows seamless testing across all devices simultaneously, will have worked with responsive design in some shape or form. And as today's websites and devices become ever more varied, a plethora of responsive images...
![Create Digg URLs Using PHP]()
Digg recently came out with a sweet new feature that allows users to create Tiny Digg URLs which show a Digg banner at the top allowing easy access to vote for the article from the page. While I love visiting Digg every once in a...
![Get Slick with MooTools Kwicks]()
When I first saw MooTools graphical navigation, I was impressed. I thought it was a very simple yet creative way of using Flash. When I right-clicked and saw that it was JavaScript, I was floored. How could they achieve such...
Is the resulting value always a string or an integer except when unspecified (then it is a string), and are the values you stated the same cross-browser (especially the unspecified value)?
I really like how medium handles DNT.