Meta tags represent the beginning of most SEO training, for better or for worse. I contemplated exactly how to introduce this topic because we always hear about the bad side of meta tags — namely, the keywords meta tag. One of the first things dissected in any site review is the misuse of meta tags, mainly because they're at the top of every page in the header and are therefore the first thing seen. But we don't want to get too negative; meta tags are some of the best tools in a search marketer's repertoire.

There are meta tags beyond just description and keywords, though those two are picked on the most. I've broken down the most-used (in my experience) by the good, the bad, and the indifferent. You'll notice that the list gets longer as we get to the bad ones. I didn't get to cover all of the meta tags possible to add, but there's a comprehensive meta tag resource you should check out if you're interested in everything that's out there.

My main piece of advice: stick to the core minimum. Don't add meta tags you don't need — they just take up code space. The less code you have, the better. Think of your page code as a set of step-by-step directions to get somewhere, but for a browser. Extraneous meta tags are the annoying "Go straight for 200 feet" line items in driving directions that simply tell you to stay on the same road you're already on!

The good meta tags

These are the meta tags that should be on every page, no matter what. Notice that this is a small list; these are the only ones that are required, so if you can work with just these, please do.

• Meta content type – This tag is necessary to declare your character set for the page and should be present on every page. Leaving this out could impact how your page renders in the browser. A few options are listed below, but your web designer should know what's best for your site.

<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">

• Title – While the title tag doesn’t start with "meta," it is in the header and contains information that's very important to SEO. You should always have a unique title tag on every page that describes the page. Check out this post for more information on title tags.
• Meta description – The infamous meta description tag is used for one major purpose: to describe the page to searchers as they read through the SERPs. This tag doesn't influence ranking, but it's very important regardless. It's the ad copy that will determine if users click on your result. Keep it within 160 characters, and write it to catch the user's attention. Sell the page — get them to click on the result. Here's a great article on meta descriptions that goes into more detail.
• Viewport – In this mobile world, you should be specifying the viewport. If you don’t, you run the risk of having a poor mobile experience — the Google PageSpeed Insights Tool will tell you more about it. The standard tag is:

<meta name=viewport content="width=device-width, initial-scale=1">

The indifferent meta tags

Different sites will need to use these in specific circumstances, but if you can go without, please do.

• Social meta tags – I'm leaving these out. OpenGraph and Twitter data are important to sharing, but are not required per se.
• Robots – One huge misconception is that you have to have a robots meta tag. Let's make this clear: In terms of indexing and link following, if you don't specify a meta robots tag, they read that as index,follow. It's only if you want to change one of those two commands that you need to add meta robots. Therefore, if you want to noindex but follow the links on the page, you would add the following tag with only the noindex, as the follow is implied. Only change what you want to be different from the norm.

<meta name="robots" content="noindex" />

• Specific bots (Googlebot) – These tags are used to give a specific bot instructions like noodp (forcing them not to use your DMOZ listing information, RIP) and noydir (same, but instead the Yahoo Directory listing information). Generally the search engines are really good at this kind of thing on their own, but if you think you need it, feel free. There have been some cases I've seen where it's necessary, but if you must, consider using the overall robots tag listed above.
• Language – The only reason to use this tag is if you're moving internationally and need to declare the main language used on the page. Check out this meta languages resource for a full list of languages you can declare.
• Geo – The last I heard, these meta tags are supported by Bing but not Google (you can target to country inside Search Console). There are three kinds: placename, position (latitude and longitude), and region.

<META NAME="geo.position" CONTENT="latitude; longitude">
<META NAME="geo.placename" CONTENT="Place Name">
<META NAME="geo.region" CONTENT="Country Subdivision Code">

• Keywords – Yes, I put this on the "indifferent" list. While no good SEO is going to recommend spending any time on this tag, there's some very small possibility it could help you somewhere. Please leave it out if you're building a site, but if it's automated, there's no reason to remove it.
• Refresh – This is the poor man's redirect and should not be used, if at all possible. You should always use a server-side 301 redirect. I know that sometimes things need to happen now, but Google is NOT a fan.
• Site verification – Your site is verified with Google and Bing, right? Who has the verification meta tags on their homepage? These are sometimes necessary because you can't get the other forms of site verification loaded, but if at all possible try to verify another way. Google allows you to verify by DNS, external file, or by linking your Google Analytics account. Bing still only allows by XML file or meta tag, so go with the file if you can.

The bad meta tags

Nothing bad will happen to your site if you use these — let me just make that clear. They're a waste of space though; even Google says so (and that was 12 years ago now!). If you're ready and willing, it might be time for some spring cleaning of your <head> area.

• Author/web author – This tag is used to name the author of the page. It's just not necessary on the page.
• Revisit after – This meta tag is a command to the robots to return to a page after a specific period of time. It's not followed by any major search engine.
• Rating – This tag is used to denote the maturity rating of content. I wrote a post about how to tag a page with adult images using a very confusing system that has since been updated (see the post's comments). It seems as if the best way to note bad images is to place them on a separate directory from other images on your site and alert Google.
• Expiration/date – "Expiration" is used to note when the page expires, and "date" is the date the page was made. Are any of your pages going to expire? Just remove them if they are (but please don't keep updating content, even contests — make it an annual contest instead!). And for "date," make an XML sitemap and keep it up to date. It's much more useful.
• Copyright – That Google article debates this with me a bit, but look at the footer of your site. I would guess it says "Copyright 20xx" in some form. Why say it twice?
• Abstract – This tag is sometimes used to place an abstract of the content and used mainly by educational pursuits.
• Distribution – The "distribution" value is supposedly used to control who can access the document, typically set to "global." It's inherently implied that if the page is open (not password-protected, like on an intranet) that it's meant for the world. Go with it, and leave the tag off the page.
• Generator – This is used to note what program created the page. Like "author," it's useless.
• Cache control – This tag is set in hopes of controlling when and how often a page is cached in the browser. It's best to do this in the HTTP header.
• Resource type – This is used to name the type of resource the page is, like "document." Save yourself time, as the DTD declaration does it for you.

There are so many meta tags out there, I’d love to hear about any you think need to be added or even removed! Shout out in the comments with suggestions or questions.