Recently there were some comments from Google that made its way to Search Engine Journal describing the preference for rendering Schema Markup JSON-LD server side. The recommendation is that publishers should place the JSON-LD on the server side within the HTML. This is sound advice and something we agree with.
However, the write-up and interpretation are more drastic than reality. It overlooks the slow release time and iterations of backend IT software as well as the increased dependency on other parties to get the work done and the impact to the business of adopting schema markup.
In our conversations with other members of the Google team, adoption of structured data has been a high priority for them. This makes sense as they try to understand content, delighting their customers who are searching for an answer. Restricting the ways of which businesses can adopt goes against their goal to drive adoption, and therefore also doesn’t make sense.
What we take away from John Mueller’s article is that it is preferred to have schema markup server side (and cheaper for their crawlers), but not the only way of deploying structured data.
Does using Google Tag Manager change the answer?
No, GTM is a fine method of adding schema markup. It too needs to be written and understood in the context of Google’s rendering capability. Write the code using ECMAScript 5 without any dependent libraries and you’ll probably have no issues. If you do, I’d start reviewing other libraries that are incompatible and it’s at this point you may have bigger issues with site crawl-ability anyway.
We also prefer to get markup server side. That is why we’ve created our add-ons for WordPress, Shopify, BigCommerce, and Drupal. But the reality is that the barriers and time to get those add-ons setup, can drastically slow down the return of having structured data.
What technologies drive the crawlers?
In conclusion, we recommend you adopt structured data. If you can put it server side, awesome, do it. If not, then using Tag Manager is better than not adopting it at all.