There are many SEO meta tags out there and even though search engines are nowadays so smart they can understand the content of your website without relying on the meta tags, it still makes sense to add a good quality set of tags.
Quality over quantity
That’s the advise for SEO meta tags. Stick to the minimum, and provide high quality input for those. Make sure to not have duplicated or similar content in the meta tag description, as this might hurt your SEO.
Having unique and high quality SEO meta tags signals that the content of the page is of high quality too. Or in contrast, having duplicated or non-descriptive information in your meta tags indicates that the content is poorly managed and possible automatically generated. So, a no go!
Which meta tags are relevant?
Meta content type
Meta content type explains the character set of your page and you should include it on each page.
The title is an important one and you should have a UNIQUE title on each of the pages that describes the page.
The title is displayed on search engine results pages (SERPs) and should grab the searcher’s attention. The length should be around 50-60 characters.
Meta description is very important as it is the information that is shown to searchers. The main goal for you is to optimize the information here so that the searcher clicks your link. The content does not influence your SEO ranking per se, but it influences whether or not the searcher will click on your link. That means it influences the click through rate. And that metric, influences your ranking in the long run. You should design it with the searcher’s intention in mind and keep it within 160 characters.
Viewport is important to ensure a good mobile experience. The standard tag is:
<meta name="viewport" content="width=device-width, initial-scale=1" />
Robot meta tags are important if you want to change the default behavior, which is “index, follow”. If you do not want the search engine robots to index the site or follow then you should specify this. And, in case you wonder, yes, it totally makes sense to limit index and follow to a subset of your pages.
Pages such as login or thank you pages do not need to be indexed, as the seldomly contain interesting content and indexing those can hurt your SEO. Most of the time, you can safely allow to follow links. You should only restrict the following of the links, if the content for the link is untrusted or if the link is paid. But then again, it is much better to nofollow on a per link basis instead of using the nofollow attribute on the whole page. Click here to learn more about when and how to restrict the following of a link.
<meta name="robots" content="noindex" />
Social meta tags
I would definitely recommend to specify social media tags, because they define how you website appears whenever it is shared. And of course, you want it to look good. This is like a free advertisement for your page, and even better. Each share means more inbound links, and those let you climb the ranking hill.