Kentico Xperience 13 documentation and ASP.NET Core

Most documentation about running Xperience applications under ASP.NET Core can be found in a dedicated section: Developing Xperience applications using ASP.NET Core. The rest of the documentation still applies, but some code samples and scenarios might need slight modifications for Core projects.

Certain pages allow you to switch between Core and MVC 5 content using a selector located under the page heading.

All major differences between the MVC 5 and Core platforms are summarized in Migrating to ASP.NET Core.


Validating CSS

The system allows you to validate the CSS style definitions used on pages against the CSS3 standard. The validator checks the styles declared in the head section of the page code.

Inline styles declared as attributes of individual HTML elements are not validated.

To validate a page's CSS:

Warning: During validation, your data is sent to an external 3rd party validation service. If you have sensitive, non‑public content, we recommend using other types of validation.

  1. Open the Pages application.
  2. Select the page in the content tree.
  3. Switch to the Preview mode.
  4. Open the Validate -> CSS tab.
  5. Click Validate.

If the validator finds invalid style definitions, the page displays a list of all detected issues. You can see the following information for each issue:

  • Line – the approximate line number of the HTML source code where the issue was found.
  • Context – the name of the CSS class that contains the issue.
  • Error message – a message explaining the issue.
  • Source – if the issue was found in an external CSS stylesheet, a relative path to the stylesheet is displayed.


  • We recommend waiting at least 30 seconds between validation requests. If you submit a page for validation multiple times within a short interval, the validation service may temporarily block your page's URL.
  • If you navigate to another page in preview mode using links on the displayed pages and then switch to the Validate tab, the system still validates the page selected in the content tree.