When is a cookie not a cookie? When it’s one of those Cookies Having Independent Partitioned State.
Still not with us? We don’t blame you. There’s been a lot of talk about the end of the Third Party Cookies … CHIPS is one of the strategies Google is offering to help keep the internet working.
How Third Party Cookies Used to Work
Consider a third-party chat application … a frequent addition to may websites. It this instance we’ll call it chatwidget.io. With traditional, third-party cookies the widget you enabled on one website would then be able to access cookie information on the next site you visit which uses the same widget.
How CHIPS Work
CHIPS allows the third party cookie to be set in the context of the parent website. All the cookies required to make the widget can be set. But they are not available to the same widget running on a different website. For example:
Significantly, CHIPS cookie information is always bound to the context. At no point will the widget be able to access information set under another domain.
Why do Developers Need CHIPS?
There are many instances where a website needs to leverage resources from a third party website. For example:
- Chat applications – whatever their purpose (support, sales etc), chat widgets rely on a persistent state. When you navigate page to page, the conversation continues uninterrupted. Without a means of saving the conversation state, this would be impossible.
- Third-party payment embeds typically need access to the original transaction token to complete payment successfully
- A Content Delivery Network (CDN) is likely to want to set a cookie for load-balancing purposes.
- Embedded Adverts where, for example, a user has set advertising preferences for that website. The adverts will still be syndicated from the advertising provider, so it needs to know what adverts the user wishes to see on example.com.
… and many more.
It’s not just that these embeds are convenient; each embedded service is a specialist provider in its own right. A chat app’s technical and legal requirements will differ significantly from those of a payment gateway. The prospect of a single development team managing both the code and the legalities of both is not pretty. We have seen it; it really isn’t …
Why are Cookies Having Independent Partitioned State Good?
Well, if it suits your needs, it’s really pretty simple to implement. When setting a cookie, the additional parameter, Partitioned, grants use of the cookie in the child process as long as it runs in the domain context.
document.cookie="__Host-name=value; Secure; Partitioned; Path=/; SameSite=None;"Code language: JavaScript (javascript)So Can We Use It Yet?
As of March 2024, CHIPS haven’t even made their way into Can I Use yet, so we suspect adoption is some way off.
At this stage, it’s a sandbox technology. Chrome and Edge both implement chips and Google is working to gain industry-wide implementation. But Safari still has a very significant proportion of all mobile use. So, without buy-in from Apple, the technology might not go far.