Does using instant.page really improve website speed?

[AlbertBenj]

Did anyone use instant.page ?

Adding it on my website doesn't show a real improvement when I check it on PageSpeed Insights. 

[jameskosh · Accepted solution]

It doesn't work with Shopify websites because Shopify adds an HTTP header that prevents caching their pages (instant.page works by precaches pages before the user visits them). Also, you will not be able to see score change with PageSpeed Insights by adding instant.page to any website because instant.page only leads to improvements after a user attempts to navigate to another page, which isn't a thing PageSpeed Insights tests.