Navigating Marketo’s URL Deprecation: Protecting Your Marketing Assets and Leads

Has your marketing operations team updated old design studio URLs created prior to 2021? If not, your forms, images, and files are more than likely impacted.

BY: Lindsay Fay

PUBLISHED: 9/5/2023

In 2021, Marketo announced that they would be deprecating usage of old URL structures starting in August of 2023, causing assets (images, files, and forms) created in 2021 or earlier to break or no longer load.

Now, what’s the impact for marketing operations teams and should you be concerned? 

If the following applies to your team, then your forms, images, and files are more than likely impacted:

  • Your instance was created in 2021 or earlier 
  • You have legacy assets, templates, gated content, or forms created in 2021 or earlier that are still in use today
  • Those assets were created before you configured a CNAME in Marketo


Most marketing operations teams don’t document every used-by reference for forms and images – especially when those assets are being embedded into external websites, program templates, or even hardcoded into design studio templates.

Some organizations have thousands of active forms and templates that then get cloned and re-used. For example, forms can get embedded in external web pages on a corporate CMS and images can be hardcoded into email templates. Marketo offers no way to track what is in use, or where. 

This leads to every marketer's worst nightmare – nurture programs containing broken files, contact forms no longer working, and broken images in emails – which can lead to brand damage and the loss of high value, inbound leads.

Ahead of the 2023 URL deprecation, MERGE assessed all clients, notified those who were likely to be impacted, and worked with them using advanced automation techniques to identify and replace affected assets. 


The details of the solution

MERGE’s Senior Technical Consultant Paul Ferrer architected a two-fold solution that searched 50,000-60,000 emails for broken links and identified 639 web pages to include a new form embed code in just a few days.  

Marketo Forms


  • In order to identify forms currently in use, we extracted the last 13 months of form fill data via Marketo’s bulk activity extract REST API endpoint. This provided the IDs of each form which was filled out, as well as the referring URL which shows the page the form fill occurred on.
  • We next pulled a list of forms from Marketo using the REST API GET Forms endpoint. Forms created after 2021 were discarded as they are unaffected.
  • We cross-referenced the list of pre-2021 forms with the list of forms filled out in the last 13 months to identify pages which would potentially need to have the embed code updated.
  • Using a Python script, we pulled down the content of the candidate pages to identify which referring URLs contained the soon to be deprecated embed code structure in the html of the page.
  • From here, we either provided the list of affected pages to our clients teams to be actioned on or worked with MERGE’s EEP (Experience, Engineering, and Platforms) Development team to update the pages internally. 


Emails and Images

  • To view emails and images with old design studio URLs, we began by pulling email performance data over the last year to identify email assets in use.
  • We identified which emails were created prior to 2021, then cross referenced the sent emails with the ones created before 2021.
  • From here, we used Javascript in the browser console to generate email previews and pull preview html. We searched for the offending URL structures in each of those emails by using regular expressions and checked if any legacy image URLs were present. 
  • We notified our clients of affected emails and worked to update the assets as required.


This custom solution quickly and accurately searched through a mass of emails and web pages that otherwise would have been prohibitively time consuming to review manually (our team estimates one person-year of effort to review). This novel approach to a Marketo UI challenge ensured  that leads continued to flow in with no disruptions to the sales funnel. 

Has your marketing operations team updated references to old design studio URLs created prior to 2021? Learn how MERGE can help expedite this process for you. Contact us today.

Curious to learn more about our Marketo consulting services? Read more here.