Google Analytics 4 differs significantly from Universal Analytics. Although the Google team makes everything to keep GA4 functionality close to Universal Analytics (internal traffic filter, for instance), it still doesn’t have all the features UA had.
One of these features is filters. For now, you can use internal and developer traffic filters, including a hostname filter workaround I offered in another article.
Like a hostname filter that GA4 doesn’t have, Google Analytics 4 filters don’t include a lowercase filter. Therefore, I dedicate this article to present a workaround solution to you.
How to set up a lowercase filter in GA4 using GTM
To lowercase UTM parameter values, you should use Google Tag Manager. The process is straightforward and can be applied to every UTM parameter (source, medium, campaign, term, content).
Below I will show how to lowercase the utm_campaign parameter, but again, you can apply it to every parameter you send through GTM. So, here are the steps you should take.
Time needed: 10 minutes
- Open GTM and create a new variable
1. Variable Type – URL
2. Component Type – Query
3. Query Key – utm_campaign
4. Format Value – Change cases to – lowercase
5. Save it and give it the name “utm_campaign” - Open your GA4 configuration tag and make the following adjustments in “Fields to Set”:
1. Field Name – campaign
2. Value – {{utm_campaign}} (our variable we created early) - Publish the GTM container
After you make the above-mentioned changes, your GA4 property will receive the values of utm_campaign in lowercase. Of course, if all of your GA4 traffic goes through GTM and GTM is your primary way of GA4 implementation.

Final Thought
Although the Google team makes everything to transit the most popular UA features to GA4, GA4 still doesn’t have all the necessary filters we had in UA. Therefore, this article presents you with a workaround solution you can use. If you find it helpful, please help me to grow my blog by leaving a comment below.
GA4 doesn’t have a lowercase filter yet, BUT you can use Google Tag Manager to lowercase UTM parameter values.
Very cool, thank you, but what if I needed to lower case search terms? I would add “search_term” to the part “3. Query Key” but what would I add to “1. Field Name” ?
I am trying to figure out this exact thing. Any luck with the lower case filter for search terms?
Hi Meagan,
Please see the answer below.
Hi Peter,
Thank you for the question.
In this case, you should deactivate the site search in Enhanced Measurement and add it manually using GTM. So do the following:
1) Deactivate “Site search” in Enhanced Measurement
2) Create the GA4 event tag in GTM: event name “view_search_results”, event_property “search_term”.
3) Lowercase “search_term” using GTM lowercase feature.
4) Publish GTM container.
Let me know if you have any questions.
Ihar
Hi Ihar,
thank you, but to be honest I tried it and got lost in the name and property. The “event name” field is there but I cant find the “event property” field when creating the tag. Would be great if you could make a manual on this too, seems many people have issues with it and I searched the web and found no manual how to fix it…
Hi Peter,
Thank you for the good idea to write about it, I will do it.
In GTM GA4 Event Tag, you have “Event name” and “Event parameters”.
“Event name” is “view_search_results”; “Parameter Name” is “search_term” and “Value” is your lowercased variable.
Ihar
thank you so much!! I will try this.
Quick question…so we follow all directions above and use search_term in place of utm_paramater. Then we do this:
1) Deactivate “Site search” in Enhanced Measurement
2) Create the GA4 event tag in GTM: event name “view_search_results”, event_property “search_term”.
3) Lowercase “search_term” using GTM lowercase feature.
4) Publish GTM container.
Do we create a new GA4 Event Tag, and set the configuration tag as GA4 Configuration, and what would the trigger be?
Hi Meagan,
Whenever you create a GA4 event in GTM, you create GA4 Event Tag. You don’t need to create a new GA4 configuration tag, you can select the one you used for other GA4 event tags.
The trigger should be the search result page in this case, but it depends on your website structure. Unfortunately, I need the link to your website to advise better.
Best regards,
Ihar