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Introduction
When a visitor clicks on an ad, a newsletter, or a sponsored link, the URL often contains tracking parameters such as utm_source, gclid or mc_cid. These elements allow you to identify the source of traffic in your analytics tools.
But in terms of performance, they can slow down page loading. Why? Because a unique URL means a different page version in the HTML cache logic.
To improve performance, Fasterize now automatically excludes a wide range of tracking parameters from the cache key. The result: faster load times for your visitors… and no changes to your analytics.
Why ignore the tracking parameters in the cache key?
Whenever a parameter changes in a URL, the HTML version of the page is considered different, which triggers a new server-side page generation. This is useful in some cases (personalization, specific processing), but unnecessary in the vast majority of marketing campaigns.
Let's take an example:
<https://www.monsite.com/landing?utm_source=newsletter&utm_medium=email>
Without optimization, this URL generates its own cached version, separate from:
<https://www.monsite.com/landing?utm_source=google&utm_medium=cpc>
Yet in both cases, the content displayed is identical.
💡 By ignoring the tracking parameters in the cache key, Fasterize enables the HTML response to be cached, thereby serving pages after an ad click more quickly.
Which tracking parameters are now excluded?
Fasterize has expanded the list of parameters automatically excluded to optimize the cache key. Here is an overview of the platforms and parameters affected:
- AT Internet / Piano Analytics :
at_format,xtor,at_identifier, etc. - Matomo / Piwik :
mtm_source,mtm_campaign,mtm_kwd… - Google Ads, TikTok, Microsoft Ads :
gclid,ttclid,msclkid,gbraid… - Email marketing (Mailchimp, etc.) :
mc_cid,mc_eid - Affiliate / Other Tools :
cjevent,cmpid,epik,IATA…
💡 These parameters remain visible in the URL and are always interpreted correctly by your analytics tools.
A complete list, including parameters that were previously excluded, is available in the following documentation:
👉 View the complete list of parameters excluded from the HTML cache
Is there anything I need to do on my end?
Fasterize applies this optimization in a completely transparent manner. Your visitors see the same pages. Your tools receive the same data.
⚠️ Note: Are you using certain settings to customize content on the server side?
Example: You display a specific block if utm_source=newsletter.
In that case, you can request that these settings be stored in the cache key via a dedicated configuration. If you're unsure, our support team can help you verify this.
Conclusion
This change in HTML cache management allows you to:
- Speed up your landing pages from marketing campaigns
- To reduce server load through improved resource sharing
- To preserve all your analytics data
And in most cases, you don't have to do a thing.
This is a concrete example of the automatic optimization implemented by Fasterize to improve both performance and ease of use.