What is the API for?
The Search Console URL Testing Tools API enables you to run various performance and validation checks against a single web page. These tests run as a non-logged-in user, with permissions of the Googlebot crawler; this means that if your page is roboted to prevent access by Googlebot, these tests will not work.
What tests does it have?
The following tests are exposed by the Search Console URL Testing Tools API:
|API test||Description||Equivalent browser-based test|
Test whether a page works well on a mobile device. Learn more about mobile usability.
To see a report showing mobile-friendliness issues for an entire website, verify your site on Search Console and read the Mobile Usability report.