Recently a new customer for JSON-LD for SEO was asking about product tags and their role with SEO.
We have 20 product tags per product which are keyword rich - is the only way to get these indexed by google to have them on the product images - surely they can show on their own for SEO.
Product tags alone don't do much for SEO. They are just a way to organize products inside of Shopify and in some Shopify themes aren't ever shown on the page, making them invisible to customers and Google.
Now, if you use them on your product page or link to your tagged collections pages they might impact SEO.
Product tags as keywords in page content
If your theme lists the product tags on the product page, they can become page content that Google will read.
Google will read a page just like a person would so if your tags are listed in the main product area, they'll be read by Google and count towards the amount of content on the page.
If they are lower down on the page or in a tiny font they'll still count, but less than before.
And if they are hidden or only in the meta tags (or worse the
meta keywords tag that's been unused for decades) then there's a good chance Google will ignore them completely.
You need to be careful because if they represent a large portion of the page's total content, Google might think you are doing what's called 'keyword stuffing' which is a very easy way to get penalized.
A few tags are fine but if each product has 20+, I'd be concerned unless you add more content to the page (e.g. production description).
And really when Shopify stores talk about page content, 80-90% of that should be coming from your product descriptions on product pages, page and blog post body content, etc. Even 20 different words in your tags should be only a small portion of the content on your pages.
Product tags as keywords in the url
The other way product tags could help with SEO is through how Shopify creates urls. Collections can be browsed by tag and they get a url that includes the tag name like
The keywords used in a url are a ranking factor so with a keyword-rich tag and collection name, that could be a valuable url for SEO.
In order for that to work though, you'll also need unique content along with it. If every collection page and tag has the same or near identical content, Google will ignore most of them and won't rank them very well.
This is the often written about "duplicate content penalty" but in reality it's not a penalty. Google just ignores what they consider the copied urls. That still hurts your SEO but it's not as damaging as an actual Google penalty (you'd feel those).
To get back to the customer's question, yes product tags can help with SEO but really, they are just treated as content by Google. And more content is always better as long as it's quality and unique content.
Use your tags if it only takes a few minutes, but invest your time into writing better product descriptions. That's what will really help your SEO in the long-term.