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.