Upcoming changes to how CSS for custom Qlik Analytics themes is handled

[Sonja_Bauernfeind]

Qlik is introducing changes to how custom themes in Qlik Analytics applications are handled, which may impact your CSS-styled themes if they include unsupported CSS modifications. This also applies to other means of modifying the CSS, such as the sheet input box, the Multi KPI CSS input, or any other 3rd party extension that allows CSS input. 

These changes will impact both Qlik Cloud Analytics and Qlik Sense Enterprise on Windows.

For more information about custom themes, see Uploading and managing themes.

Why are these changes being made?

These changes improve how theming works in Qlik Analytics applications, which will enable us to deliver better-looking dashboards and generally enhanced theming.

What is being changed?

We’re restructuring theme settings:

• Removal of base card CSS overrides
• A theme with the _cards:true setting gets the base styles imported as JSON into the theme
• Removal of extra title padding for objects without title in a cards theme
• Replace the following with theme JSON settings:
  • padding: applied on object level; the gap between border and object
  • margin: applied on sheet level; the gap between objects

And we are adding new themes:

• Foundation (default)
• New Horizon

How can I verify if my themes are affected?

1. Open any app that uses your custom theme and append the following to the URL:  /feature/CLIENT_TLV_1804_LESS_CARDS 
   
   This will enable the flag to run your themes with the changes before they are released.
   
   
   
   
2. Verify that everything looks as you expect it to
3. Review your browser's developer tools for any eventual JavaScript errors 

Future-proof your themes

We’ve compiled a list of supported styling options for you that can already replace the need for custom CSS. See Obsolete CSS modifications.

Additionally, see the table below for an overview of the new theme properties that you can use in your theme instead of CSS. You will first need to enable the /feature/CLIENT_TLV_1804_LESS_CARDS flag to see them in effect in the application.

Theme Option	Path in theme JSON	Example
Sheet background	sheet.backgroundColor	"sheet": { "backgroundColor": "#f2f2f2" }
Sheet margin	sheet.margin	"sheet": { "margin": "10px" }
Object paddings	object.padding	"object": { "padding": "20px" // or "10px 10px 5px 10px" }
Borders	object.borderWidth	"object": { "borderWidth": "1px" }
	object.borderColor	"object": { "borderColor": "#d9d9d9" }
	object.borderRadius	"object": { "borderWidth": "3px" }
Shadows	object.shadow.boxShadow	"object": { "shadow": { "boxShadow": "0px 4px 10px 0px", "boxShadowColor": "#d9d9d9"  } }
	object.shadow.boxShadowColor	"object": { "shadow": { "boxShadow": "0px 4px 10px 0px", "boxShadowColor": "#d9d9d9"  } }

To give you more context: Document Object Model (DOM) selectors in custom CSS are not a supported pattern. While they can be helpful for customizing the look and feel of applications, the DOM is subject to change at any time. To provide your feedback, raise tickets on the Qlik Ideation portal when you need custom CSS customization. This helps prioritize supported customization options to add to the platform.

Do not use top-level selectors such as qv-client or qv-card. These selectors are planned for removal in future versions. See CSS best practices for Sense themes for more information.

What action do I need to take and when?

Qlik Cloud will see the changes on or after June 1st, 2026, while Qlik Sense Enterprise on Windows will be aligned in the November 2026 release.

While we do not expect your themes to be affected, we recommend testing them at the earliest. See the How can I verify if my themes are affected? section.

If you have any questions, we're happy to assist. Reply to this blog post or take your queries to our Support Chat.

Thank you for choosing Qlik,
Qlik Support