SEO 101: Keyword Research Volumes

SEO Couch
Search volume is one of the most important and probably the most frequently used metric in SEO. Entire businesses are being built out of the popularity of certain search queries in Google.

But as more and more keyword research tools enter the market, users start noticing that different tools report different search volumes for the same keywords.

And, most importantly, these search volumes are often different from what Google Keyword Planner is showing (which most people regard as the only accurate source of keyword data).

How accurate is the keyword search volume in Ahrefs?”

Our support team gets this question almost every other day. So I decided to address it here in all possible detail.


It’s no secret that the vast majority of keyword research tools get their data from Google Keyword Planner (directly, or via the services that scrape this data and re-sell it).

So, if everyone is using GKP as their source, how come different tools report different search volumes for the same keywords?

And why, in most cases, does it not match what Google Keyword Planner shows?

As you can see, it’s been losing its popularity lately, so the annual average in Google Keyword Planner is getting a bit smaller each month.

This means that all keyword tools that use GKP as their source have to update the search volumes of all their keywords once a month in order to provide you with the most “accurate” data.

Which is quite a challenge if you have a few million (or billion) keywords in your database, because Google does not have an API for pulling search volume.

That’s why no tool in the above comparison table reported the right search volume for all 6 keywords — they just don’t update their database frequently enough.


Most users would be perfectly happy if their keyword tool of choice would always display the same numbers that they see in Google AdWords.

But professional SEOs have always been questioning the data that they get from Google: “Google Keyword Planner’s Dirty Secrets.”

Here’s the official definition of the search volume in GKP:

“The average number of searches for this keyword and its close variants based on the targeting settings and date range you’ve selected. You can use this information to see how popular your keywords are during a certain time of the year.”

So let’s dive a bit deeper and see what’s behind that definition.


Annual average” is a rather fun thing on its own.

I mean look at the keyword “Christmas”, that has a search volume of 550,000 according to Google.

So how useful is that “annual average” here?

Christmas” is of course an extreme case, but you get the point. Most of the search queries don’t have a flat search volume trend all year long, so the “annual average” might be way different from next month’s value.


Let’s go back to the annual trend for the search query “independent films”:

Half of these bars report the search volume of 2,400 and the other half says 2,900.

You don’t have to be Grigori Perelman to calculate the average of 2,650 across 12 months of data.

But GKP search volume for “independent films” is actually 2,400, which is off by 250 searches.

Well, that’s because the annual average that GKP shows is rounded into “buckets.”

Which makes an already inaccurate number even more inaccurate.


Guess what happens if I put these 3 search queries into GKP:

So Google won’t show me if there’s any difference in search popularity between these three searches. Which makes a big difference if you want to rank organically, because the search results for these three queries differ quite a bit.

But for AdWords advertisers the difference in organic search results doesn’t matter, since their ads are always on top. So Google Keyword Planner makes things useful for advertisers, but not SEOs.


The “rounded annual average” that you see in Google Keyword Planner is actually not the only way that you can gauge the search popularity of a keyword.

They also have this tool called Performance forecasts.

I tested quite a few keywords in this forecaster tool, and the number of impressions was always different from the original search volume. Which is kind of fun.

But that fun doesn’t end there.

There’s one more source of search volume data in Google, but it only works for the keywords that your website is already ranking for.

I’m talking about the Google Search Console.

I got 19,766 impressions for that keyword in the last 28 days (from all countries). But GKP reports the search volume of 22,200 searches per month for that keyword, which is quite higher.

So I took 5 keywords that consistently ranks for in top5 search results and compared the data from three Google sources (in the United States):

  • Google Keyword Planner;
  • Performance forecasts (in Google Keyword Planner);
  • Google Search Console.
  • sources.

And there’s also no way to tell which of these sources is the most accurate.


Common sense tells us that Google is the only possible source of keyword data, because they are the only ones who know how many times people around the world search for different things.

Is there any other way to learn what people search for in Google?

Yes and no.

YES, because some applications that you install on your computer and plugins that you add to your browser request your permission to collect certain data from you.

This is called clickstream.

Then these apps and plugins sell their clickstream data to bigger companies. These bigger companies aggregate data from as many sources as they can in order to re-sell that big pile to companies like Ahrefs, which in turn do all sorts of cool things with it.

NO, because the number of people in the world who have “clickstream apps” on their computers is relatively small.


In case you got worried that someone (besides Google, Apple & Microsoft) might be tracking you — relax. All legit applications only collect anonymised clickstream data. And then they mix your data with my data, so they know what both of us searched for in Google, but they don’t know who exactly searched what.

So, all in all, raw clickstream can’t be considered as a reliable source of data, even if you find all re-sellers and buy all clickstream data that is available.

But clickstream data is super useful when you cross-reference it with data from Google Keyword Planner.

Which is exactly what we do here at Ahrefs.

Blog Source: Ahrefs | Keyword Search Volume: Things you didn’t know you don’t know

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I’m Joseph, and I started this blog as a way to share ideas with others. I wanted to create a space where people could share their thoughts and feelings, and where we could all have a good laugh. Since then, the blog has grown into something much larger than I ever imagined. We have posts on everything from humorous essays to comics to interviews. And our weekly columns cover sports, video games, college life, and software.
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