Since Coral is embedded in an article page using an iframe, we often get asked what affect, if any, iframes have on a publisher’s SEO. We asked Hart Van Santvoord, Vox Media’s resident SEO expert to give us some insight to help answer these questions.
We can confidently say that today's modern crawlers are able to crawl and index content in iframes and that they do their best to associate the two and identify which version is preferred. This isn’t as relevant however for content that is complementary to an article, such as comments here in Coral’s case, or with other embedded content like documents or live blogs. It’s is more important for products or people who are iframing entire pages, such as for syndication.
When newsrooms and organizations come to us with SEO questions, it usually falls into 2 use cases.
- We need our comments to be indexed to help our SEO!
For this case, we are very confident that the way Coral is currently handling comments via iframe provides the SEO benefit publishers are looking for:
- Google can crawl it and associate it with the container article/page
- They're certainly seeing commenting activity as a positive sign of engagement which Google cares about A LOT
- Ongoing commenting also indicates to google that the page is evolving/updating, another strong signal
- Serving via iframe typically improves performance as opposed to including the content directly on the parent page, and faster/better speed and UX is yet another strong positive signal to Google
For an example of how the Vox Media SEO team has analyzed iframe content outside of Coral, we can look at The Verge. The Verge leverages live blogging for certain types of events, such as iPhone events. In this case, similar to Coral, the live blog content itself is embedded on The Verge article via iframe but no doubt leads to a more engaged audience who stick around longer, refreshes, clicks load more, etc. We see these articles perform well in search in a super competitive space on event days.
That brings us to our 2nd use case:
- Please, make sure my comments are NOT indexed!
In this request, the use case is slightly more complicated due to the fact we know Google can crawl and index comment content. But, given that Coral does not also create creating a page just with the comments, we don’t see a chance Google would Surface just comment content in search results outside of the article in which they’re embedded.
If you’re a publisher in this scenario and are worried about the content in comments reflecting poorly on your site/brand then this seems to be as much as moderation issue As a Google one, and again, Coral does not provide a way for Google to crawl, index, and serve up commenting content outside the context of the article regardless.
If you are a newsroom doing creative things with your comments and perhaps would Have the need to create a separate page with only comments, then you can certainly explore Using tools like a canonical tag to redirect that page back to the container page, and other SEO best practices for this and other edge cases.
As of May 2021, Google includes page experience metrics in their search ranking algorithm.
One of the aspects contributing to page experience is Cumulative Layout Score, or CLS. As Coral embeds are rendered after the initial render and are dynamically sized, they may contribute to layout shifts, but in our experience Coral usually has a minimal impact on CLS. Google only counts layout shifts on visible elements, and Coral is most likely to only impact the position of elements that are below the bottom of the viewport.
If you are concerned about CLS and want to ensure that Coral does not cause layout shifts, you may want to set a minimum height on the element Coral is rendered into, to reserve space for the embed.