Meta Description Length
As of December 2017, meta descriptions should be about 50 to 300 characters.
In the past, the general rule of thumb was to keep meta descriptions under 165 characters. (about three lines in the search results).
However, Google has changed the rules here and they have expanded meta description size. What used to be about three lines, it’s being expanded to four, five, sometimes six lines depending on the query.
The idea here is that Google is always trying to render the perfect results for users and provide them with the answer to their question. So, what Google has concluded is that sometimes a really well written, long meta description solves the user’s answer and they won’t even have to click.
Meta Description Uniqueness
Meta descriptions should be unique for each page. You shouldn’t be writing one meta description and put it everywhere because duplicate meta descriptions just don’t bring you any kind of justice.
Ideally, you would be handwriting every single meta description on your site.
If you can’t do that and you have engineering experience, or you’re doing optimization on a web application, do make sure to use variables that make it unique.
Meta Descriptions: Using Keywords
You want to use your main keyword.
Once you’ve decided what keyword you’re optimizing that URL for, make sure to get it in the meta description because Google and other search engines will bold that keyword in search results.
Consequently, the users’ eyes are more likely to be attracted by that word if it’s bolded. So, if you can, do try and get your primary word in the meta description. However, keep in mind that keyword stuffing (in any of the meta tags or the body of the text, for that matter) is really something you don’t want to do.
Meta Descriptions: Are They a Ranking Factor?
Your meta description, in general, doesn’t impact the rankings and they are not a factor in the ranking algorithms – but they might help with the user experience when they enter a search query on Google or any other search engine. So, according to SEO best practices, you should definitely put some work into crafting a great meta description for each of your pages.
Whether you have your keyword in there or not, it’s not going to move you up and down search results directly. It’s not a direct ranking factor in the SERPs of Google or any other search engines (like Bing, for example).
However, it is incredibly important from a click-through rate perspective and that can affect rankings. The average user is only going to give you about one to two seconds before they decide whether or not they want to click you.
In this respect, your meta description is similar to the old-school billboard on the highway.
You’re driving down the highway, you look up at a billboard.
You’re only going to give it a couple of seconds and it may or may not have an impact on you. This is the digital equivalent of your billboard.
Users are scanning and they’re probably not reading the whole thing—so if your meta description is compelling, interesting, and it looks like it’s going to answer their question, you’re going to see an increase in click-through rate.
Will Google Use Your Meta-Descriptions All the Time?
Another important thing to keep in mind here is that Google reserves the right to not use your meta-description.
You may be investing a lot of time into crafting really compelling meta descriptions—but the truth is that somewhere between two thirds and half of the time, Google will not even use them.
They will crawl your website, they will look for some text or copy that looks relevant to the user’s query, and they will supplicate that as your meta descriptions.
Even so, you do want to write really good, compelling meta descriptions.
You want to assume that Google is going to use them, and, at the same time, be they won’t do it all the time. There’s really not a lot you can do there—maybe just send Larry and Sergey an email.
Meta Description Walkthrough
Here’s an example of a meta-description: let’s say I’m creating a page and optimize it for the term “SEO Checklist”.
The title tag for the webpage is “The Insanely powerful 2019 SEO Checklist”, and the meta-description I would use is “Starting a new site from scratch or just launching a single page? Either way, use this insanely powerful 2019 SEO checklist”.
Here’s the way it would look in the search engine results, as well as how the HTML code would look: