You can use /amp/#development=1
But even if everything is OK with Google validator how can you be sure that your pages are going to be displayed as AMP cards in Google SERPs.
This page is not in google AMP CDN
How to test your AMP page on your mobile ?
Here is a test you can do on your smartphone to check easily if your AMP page is in Google AMP content delivery network :
1st Test – If you are using a CMS such as WordPress or if you know the URL of the AMP page you want to test. You just need to paste the root of your URL into Google URL in the following way:
DO NOT USE http://www and https://www
This test with a french news website: for http://m.20minutes.fr/amp/a/1798787
Here’s url of the amp page path into Google :
Page amp in CDN google for 20 minutes
If your page appear this means its AMP valid and the should appear in Google the following way:
Amp Card in google carroussel ?Having Amp page in google amp cache doen’t necessarily mean google will display it in the carousel. So far, I’ve only seen AMP card on AMP page with News markup.
AMP Pages are also listed https://cdn.ampproject.com
If the page you sent to google is not valid you shold see the following error message appearing along with a link to the Google tool to debug your code.
Sorry this Page is not valid AMP HTML in google cache
Thx to @SEOmuscle for translation