Hreflang is used at a page level, not at a site level. So no, you should not just set the hreflang tag on every page of www.mywebsite.com to read:

So yes, if the German translation of the page www.mywebsite.com/page.html is available at www.mywebsite.de/page.html then you must do 2 things:

1. On www.mywebsite.com/page.html  use  <link rel='alternate' hreflang='de' href='http: mywebsite.de="" page.html'="">and <link rel='alternate' hreflang='en' href='http: mywebsite.com="" page.html'=""></link rel='alternate' hreflang='en' href='http:></link rel='alternate' hreflang='de' href='http:>

2. On www.mywebsite.de/page.html  <link rel='alternate' hreflang='en' href='http: mywebsite.com="" page.html'="">and <link rel='alternate' hreflang='de' href='http: mywebsite.de="" page.html'=""> </link rel='alternate' hreflang='de' href='http:></link rel='alternate' hreflang='en' href='http:>

What this means is that the English page should link to itself and to all other language variants. And there should be "return tags", i.e. each of the language variations should link to themselves and to all other language variants.

You are right. I didn't know about the right way to paginate with canonical. But the point about Hreflang stands. Don't use Hreflang and canonical together on the same page. If you are using canonical to point to the "View All" version, then use Hreflang on the "View all" versions, and not on the individual pages.

Redirects should be avoided. If the Japanese translation of your page is located at www.domain.co.jp/it-セキュリティ/ then please don't use www.domain.co.jp/it-security/ in your hreflang tag.

If it's hard to specify the correct URL in your page HTML, try providing Hreflang info in sitemaps instead.

Don't use canonical and hreflang together. I blogged about this very issue: https://hreflang.org/use-hreflang-canonical-together/

What this means for you is that even for Page-2 (for both US and CA), if you are using rel canonical to say that Page-2 is a duplicate of Page-1, then do not use hreflang on Page-2. Using both canonical and hreflang on page-2 will only confuse Googlebot.

In your case, only use hreflang on the canonical versions of the page. i.e., Page-1 on both US and CA sites should point to each other using hreflang. Page-2 and Page-3 on the US site should use rel canonical to point to US Page-1. And Page-2 on CA site should use rel canonical to point to Page-1 on CA.

You are right. I didn't know about the right way to paginate with canonical. But the point about Hreflang stands. Don't use Hreflang and canonical together on the same page. If you are using canonical to point to the "View All" version, then use Hreflang on the "View all" versions, and not on the individual pages.

Hreflang is used at a page level, not at a site level. So no, you should not just set the hreflang tag on every page of www.mywebsite.com to read:

So yes, if the German translation of the page www.mywebsite.com/page.html is available at www.mywebsite.de/page.html then you must do 2 things:

1. On www.mywebsite.com/page.html  use  <link rel='alternate' hreflang='de' href='http: mywebsite.de="" page.html'="">and <link rel='alternate' hreflang='en' href='http: mywebsite.com="" page.html'=""></link rel='alternate' hreflang='en' href='http:></link rel='alternate' hreflang='de' href='http:>

2. On www.mywebsite.de/page.html  <link rel='alternate' hreflang='en' href='http: mywebsite.com="" page.html'="">and <link rel='alternate' hreflang='de' href='http: mywebsite.de="" page.html'=""> </link rel='alternate' hreflang='de' href='http:></link rel='alternate' hreflang='en' href='http:>

What this means is that the English page should link to itself and to all other language variants. And there should be "return tags", i.e. each of the language variations should link to themselves and to all other language variants.

Don't use canonical and hreflang together. I blogged about this very issue: https://hreflang.org/use-hreflang-canonical-together/

What this means for you is that even for Page-2 (for both US and CA), if you are using rel canonical to say that Page-2 is a duplicate of Page-1, then do not use hreflang on Page-2. Using both canonical and hreflang on page-2 will only confuse Googlebot.

In your case, only use hreflang on the canonical versions of the page. i.e., Page-1 on both US and CA sites should point to each other using hreflang. Page-2 and Page-3 on the US site should use rel canonical to point to US Page-1. And Page-2 on CA site should use rel canonical to point to Page-1 on CA.