Skip to main content
J
Problem Solver I
jhorngacher
Problem Solver I
March 25, 2025
Solved

Using the Content API to update HTML, makes the preview not being newly generated

  • March 25, 2025
  • 2 replies
  • 71 views

I am trying to figure out the following problem:
- I have created a HTML-Template via API which is a code-only template ( stored the reference ID )
- Now I update the contents of it with freshly generated html via API( working fine )
- Finally I am going to check if the preview is loaded correctly and check the results with a testing profile. Right here I am stuck. There’s no preview generated anymore, if I selected a profile which includes the necessary properties for testing I also don’t get a preview. It just shows me a white page.

Fun fact, if I save the template via editor once without changing the code, the preview is then working perfectly again.

 

Is anyone able to provide me a solution?

Thanks in Advance!

    Best answer by jhorngacher

    Hi ​@emma.owens!
    Exactly, I’ve already found the issue. I forgot to have enclosing <html>and <body>  tags. 
    So for anyone having the same struggle put inside the payload of the html-content a starting <html> and <body> tag and u’re good-to-go

    <html>
          <body>
                 your additonal code goes here 
          </body>
    </html>

     

    2 replies

    emma.owens
    Community Manager
    emma.owens
    Community Manager
    March 26, 2025

    Hi ​@jhorngacher ! Thank you for reaching out to Community, and sorry to hear you’re having issues previewing your HTML email template. 

    To clarify, when you preview the email in Klaviyo is it just showing as a blank screen? And then once you save the template and go back to preview, it then shows? 

    J
    Problem Solver I
    jhorngacherAuthorAnswer
    Problem Solver I
    March 31, 2025

    Hi ​@emma.owens!
    Exactly, I’ve already found the issue. I forgot to have enclosing <html>and <body>  tags. 
    So for anyone having the same struggle put inside the payload of the html-content a starting <html> and <body> tag and u’re good-to-go

    <html>
          <body>
                 your additonal code goes here 
          </body>
    </html>

     

    Terms & ConditionsAccessibility statement

    Links & Resources

    Platforms

    Partners

    Useful Things

    About

    • Terms and Privacy |
      © 2026 Klaviyo All rights reserved. Klaviyo and the Klaviyo logo are trademarks or registered trademarks of Klaviyo, Inc. or its affiliates.