SEO Issue due to using Polymer 2.0

[Yuen92]

Description

All your components using Polymer 2.0 doesn't render by Google Bot.
You can figure it using "Fetch as Google and Render" in Google Search Console :
https://support.google.com/webmasters/answer/6066468

You get the same result using Google Speed Insights :
https://developers.google.com/speed/pagespeed/insights/?hl=fr&url=https%3A%2F%2Fhn-polymer-2.firebaseapp.com%2F&tab=mobile

So all your component "" doesn't render for Google Bot so it will be a serious SEO issue.

Expected outcome

"Fetch as Google and Render" in Google Search Console should be render the same html as the visitor see in his browser.

Actual outcome

"Fetch as Google and Render" in Google Search Console render only the root page (index.html) without the html contained in all :

Live Demo

You can see the issue with Google Page Speed Insights : (same behavior as Google Bot Desktop&Mobile)
https://developers.google.com/speed/pagespeed/insights/?hl=fr&url=https%3A%2F%2Fhn-polymer-2.firebaseapp.com%2F&tab=mobile

You can also see the problem with Mobile Friendly : (same behavior as Google Bot Mobile)
https://search.google.com/test/mobile-friendly?utm_source=mft&utm_medium=redirect&utm_campaign=mft-redirect&id=8EVV98SRe6QRqAcOSRWlGQ

Search Engine/Bot Affected

• Googlebot type: Desktop
• Googlebot type: Mobile: Smartphone
• Google Search Engine
• ...

Note

The issue doesn't occur when we used Polymer 1.X : https://shop-1-init.appspot.com/
Google Page Speed Insights : (same behavior as Google Bot Desktop&Mobile)
https://developers.google.com/speed/pagespeed/insights/?hl=fr&url=https%3A%2F%2Fshop-1-init.appspot.com%2F
Mobile Friendly : (same behavior as Google Bot Mobile)
https://search.google.com/test/mobile-friendly?utm_source=mft&utm_medium=redirect&utm_campaign=mft-redirect&id=Ljkcg5zCt_DLF5S4jRHb8g

Other example with the problem due to Polymer 2.0 : https://shop-init.appspot.com/
Google Page Speed Insights : (same behavior as Google Bot Desktop&Mobile)
https://developers.google.com/speed/pagespeed/insights/?hl=fr&url=https%3A%2F%2Fshop-init.appspot.com%2F
Mobile Friendly : (same behavior as Google Bot Mobile)
https://search.google.com/test/mobile-friendly?utm_source=mft&utm_medium=redirect&utm_campaign=mft-redirect&id=wUq2BA_91Kwwz5VAew2ivw

I also did a post on Polymer project issue :
Polymer/old-docs-site#940

Hello @Yuen92 , i'm with the same problem and no clue in how solve it (if it's possible). Do you have some news?

https://developers.google.com/speed/pagespeed/insights/?url=http%3A%2F%2Falbion.oaktavern.cc%2F&tab=mobile

[KiaraGrouwstra]

Seems the suggestions at Polymer/shop#135 (comment) have already been incorporated here. Does that mean this is resolved?

[fasihrana]

I'm having the same issues. None of my elements render.

I've added a WebCompnentsReady event listener to window, maybe that is the issue for me?

window.addEventListener('WebComponentsReady',function (){
//...
})

[Yuen92]

@marcelofranzen
@tycho01
The problem from the dependencie is maybe solved but you still need to build in ES5 for the SEO.
It's due to google bot use Chrome 41 :
https://developers.google.com/search/docs/guides/rendering

@fasihrana :
Do you have an url to share?
Do you have the problem with the ES5 building?

Regards

[fasihrana]

@Yuen92 My problem was that I wasn't serving a compiled app. I don't have this issue now.