What is PLS by UTM Medium
PLS by UTM Medium lens breaks down Perceived Load Speed (PLS) based on the utm_medium value found in your marketing URLs. This parameter typically reflects the traffic channel, such as email, cpc, social, referral, or organic.
By comparing PLS across mediums, you can understand which traffic sources deliver smoother user-perceived experiences and which ones struggle with slow-feeling page loads — often due to device types, network conditions, or inconsistent landing experiences.
Healthy PLS by UTM Medium sample
Should you worry
A healthy PLS by UTM medium distribution shows relatively consistent and fast perceived load speeds across your main traffic sources. Even if some mediums are naturally a bit slower (e.g. paid social or email on mobile), no single source should significantly degrade the user experience.
Watch for mediums where most of your volume lands but the PLS is high — this could silently hurt performance, especially in conversion-focused channels like paid search or email.
Unhealthy PLS by UTM Medium sample
Unhealthy results in this lens typically show up when a specific medium (like cpc or referral) has disproportionately slower PLS. This might indicate overloaded landing pages, inconsistent redirects, or user environments (e.g. mobile + poor network).
Social and email traffic may also trend slower due to embedded browsers or mobile-heavy usage. If your page isn't optimized for these conditions, users will feel the difference — and they may bounce before engaging.
Resolving unhealthy PLS by UTM Medium
Go-to action plan to resolve an unhealthy PLS by UTM Medium:
Ask Uxi to analyze your PLS by UTM Medium and suggest improvements.
Use Filters to drill into slow mediums and identify common traits (device, browser, connection).
Simulate LCP of the suspected lens to see if fixing it will resolve the PLS by UTM Medium. If yes, this is where the resolution focus should be.
Use an automated optimization tool like Navigation AI to improve your PLS by UTM Medium.
Once you’ve improved PLS, set an alert to be the first to know if it starts worsening again.
Try it yourself
Discover how your website performs with real user data.