Is hidden content bad for SEO?

[soralsokal]

I am using this plugin to enable Facebook comments on my blog:
https://wordpress.org/plugins/fatpanda-facebook-comments/

This shows the comment in an Facebook iFrame. The plugin author claims it's SEO friendly, because the comments are also integrated in the WordPress database. The are included in the post but hidden.

Is that bad for SEO?

[DeanAndrews]

A quick test for this would be to test your site in http://seo-browser.com and compare it to the same page source code (in browser right click 'View Page Source' or 'View Source' depending on browser) as I'm not sure what elements are being hidden

[soralsokal]

That's a cool tool, didn't know that yet.

I used it and also checked in the source code. The hidden content is there. But it's not visible on front end side (except the Facebook comment iFrame).

Now is that bad?

[DeanAndrews]

Generally speaking anything in an iFrame will not be indexed for your site and therefore will provide no SEO benefit. So if the hidden text is within the iFrame this will have no positive or negative effect for your site.

[soralsokal]

In this case the hidden text is not inside the iFrame (WordPress comment database), and visible in the source code.

But it's not visible in the front-end.

[DeanAndrews]

Now I'm confused, you said "But it's not visible on front end side (except the Facebook comment iFrame)." Then "the hidden text is not inside the iFrame"

In the source code do you actually see the word iFrame?

[soralsokal]

Hm, I admit it's not so easy to explain the topic. Let me summarize it like this:

My site: WordPress
Issue: Regarding comments on a blog post

Comments: Usually WordPress uses it's own commenting system. Google can see the comments and this helps for SEO.

Comments on Facebook: To increase my comment rate, I am using a Facebook commenting plugin.

How does it work: Facebook uses an iFrame for comments, so they are visible in Front-End, but not in source code. But: The plugin is smart and takes those comments and puts them into the WordPress database. So WordPress shows the comments in the source code, but not in the Front-End. Only the Facebook comments are shown in the Front-End, but since it's an iFrame not in the source code.

So from Googles perspective the comments are visible in the source code, but they can't find them displayed in the front-end. The question is if that's a bad thing. The reason for me asking is, that some time back I read that lot's of black hats are using hidden content and that you should not do it.

[Everett]

Providing an alternative way for search engines to access content that is not otherwise available to them, but is clearly available to anyone who "sees" the page is a legitimate use of the Display: None tag. Here is what Google has to say about it: http://www.seroundtable.com/google-hiding-content-17136.html .