A while back I posted a blog explaining how to create custom conversion rates and funnels in Google Data Studio. As far as I know, this is still the only way to create funnels in Data Studio. The biggest problem with this method is that it does require you to have a Session ID dimension available in your data. Not everyone does, and not everyone is able to get this added to their tracking.
So what do you do if you aren't recording Session ID? Below is a technique I've come up with to create funnels and conversion rates in Data Studio without having Session ID added to your tracking.
It still involves using a Session ID, however, instead of having to have Session ID added to our tracking we can create our own unique identifier using a calculated dimension in Data Studio. I call this technique stitchy-stitchy.
Basically what we do is concatenate a bunch of dimensions together to create a "unique" string for each session. e.g. what browser is a visitor using, what page did they land on, what time did they start their session etc.
Here is the calculation I've been using, but you're welcome to use whatever dimensions you have available to you.
concat(Browser,(concat(Browser Size,concat(Browser Version,concat(Screen Resolution,concat(City ID, concat(Landing Page,Date Hour and Minute)))))))
If you create this field and pull it into a table it should look something like this:
The dimension will be a string of all the different dimensions stuck together, and for the most part should be unique to an individual session! In the above example my calculation returned 3,017 unique IDs, and GA reported 3,023 Sessions. So not perfect, but pretty close.
To create that Session ID dimension in Data Studio just click Create New Field in the bottom right corner of the Data Tab when you have a chart selected:
And paste the above calculation into the editor:
You will then be able to use this Session ID dimension in your charts and calculations. The best part is, it's retroactive so you will be able to use it across all your past data even though you didn't have Session ID recording.
Here is an example of creating a custom metric for sessions that started on the homepage using the Session ID we have created:
But now that you have a Session ID set up, I'll direct you back to the original article on how to create a funnel.