Keyword Search Volume: Things you didn't know you don't know 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. Where do keyword research tools get their search volume data? Its 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?
Sidenote. I didnt include search volume data from Ahrefs in this comparison table, because our search volume is actually designed to be different from GKP. More on this later in this post. WARNING! Please do not use this small comparison to identify the tool that was the closest to GKP. A test of six keywords says nothing about accuracy. Id have to test at least 100k keywords to make the comparison fair. So this small experiment is just to illustrate that no tool will match GKP data in 100% of cases. The search volume that you see in Google Keyword Planner is a rounded annual average, which means they re-calculate it every month.
Lets look at the search trend for the query independent films:
As you can see, its 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. Thats why no tool in the above comparison table reported the right search volume for all 6 keywords they just dont update their database frequently enough. How accurate is the search volume in AdWords? 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 Planners Dirty Secrets. Heres 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 youve selected. You can use this information to see how popular your keywords are during a certain time of the year. So lets dive a bit deeper and see whats behind that definition. Annual average 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.
If you pull up the annual trend for that search query, youll see that it barely gets 100k searches per month for most of the year, then peaks at over 3 million in December:
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 dont have a flat search volume trend all year long, so the annual average might be way different from next months value. Buckets Lets 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 dont 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, thats because the annual average that GKP shows is rounded into buckets. Which makes an already inaccurate number even more inaccurate. Close variants
Guess what happens if I put these 3 search queries into GKP: SEOsearch engine optimizationsearch engine optimisation
They will be combined into a single keyword:
So Google wont show me if theres 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 doesnt matter, since their ads are always on top. So Google Keyword Planner makes things useful for advertisers, but not SEOs. More search volume clues in Googles tools. 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. To get there, you need to add a few search queries to your plan, and then click the Review plan button:
From there, by following a simple process described here, youll be able to get the impressions data for your list of keywords. Even for the close variants that GKP was previously hiding from you:
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 doesnt end there. Theres one more source of search volume data in Google, but it only works for the keywords that your website is already ranking for. Im talking about the Google Search Console. My article was consistently ranking in Google top3 for the keyword research search query, so I can use GSC to calculate the number of impressions it has generated in the past 28 days:
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 ahrefs.com 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.
As you can probably tell, theres not much consistency between these three sources. And theres also no way to tell which of these sources is the most accurate. Clickstream a new source of keyword data. 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. Sidenote. 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 dont know who exactly searched what. So, all in all, raw clickstream cant be considered as a reliable source of data, even if you find all resellers 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.
And heres why it is so cool: Monthly updates Thanks to clickstream, we can easily update our search volumes every single month and catch all the trends:
By the way, right now we calculate our search volume as 30-months average, but will most likely switch that to 12-months average soon. Sidenote. The search volume numbers in Ahrefs are also rounded off a bit, but that is just to make the numbers look prettier. We dont use any buckets that would distort our search volume data.Ungrouping close variants We can also un-group the close variants that Google Keyword Planner is grouping together:
Search volume Clicks The fact that people search for something doesnt mean that they will click on any of the search results.
As you can see, a lot of people were searching for Donald Trump age during the US elections, but they werent clicking on the search results, because Google has an instant answer to this query:
But theres more! Take a look at this screenshot:
How come we report nearly the same traffic from #1 position in Google for two keywords, while the search volume of these keywords differs by over 5x? Well, we use clickstream data to determine the CTR curve for every individual keyword (where we have enough data to be certain).
So for the keyword moz we see that ~55% of clicks go to #1 result. Which is expected, since its a branded search query. And for the keyword SEO we see that only ~10% of clicks will go to #1 result, because most searchers wont actually click on anything when searching for it:
That is pretty cool, right? But theres one last thing that you need to know about the search volume. WARNING: Search volume is a bad predictor of search traffic! This probably sounds super counterintuitive, but I have a great example to illustrate my point. Lets compare the search volume of these two keywords:
SEO tips has almost twice the search volume of submit website to search engines. Which kind of suggests that if you rank your article for that keyword, youre going to get twice more traffic. Right? WRONG! Lets take the top ranking pages for both search queries and plug them into Ahrefs to see how much search traffic they get in total:
Looks like the page that ranks for SEO tips gets 10x less traffic than the page that ranks for submit website to search engines, while the former has a 2x higher search volume. Thats because a web page will rarely rank in Google for a single search query alone. In fact, weve recently studied that an average ranking page will also rank for about 1000 longer-tail keywords. And heres what is happening in this particular case. SEO tips is a rather specific search query and there are not too many alternative ways to put it: Seo tips 2,700seo optimization tips 500seo tips and tricks 300google seo tip 100easy seo tips 30tips for seo 20 So the total search volume of this group of search queries is mostly condensed at SEO tips which is clearly the most comprehensive way to put it. And the overall number of these relevant search queries is rather limited, thats why the top ranking page for SEO tips is only ranking for 148 keywords in total. Submit website to search engines is very different in this sense. There are a lot of alternative ways to phrase this request, all of which sound quite plausible: submit website to search engines 1,300submit site to search engines 500submit url to search engines 500submit to search engines 300submitting site to search engines 300add website to search engines 250submitting to search engines 200submitting page to google 200submitting my website to google 200submitting your website to google 200submit urls to search engines 200& many-many more This is how the top-ranking page for submit website to search engines ranks in Google for almost 4,000 other search queries, all of which bring a ton of search traffic. And you would have never discovered this amazing traffic opportunity if youre only looking at the search volume and not analysing the top-ranking pages. Sidenote.
Heres another cool example of search queries where traffic doesnt match the search volume: cool wallpapers and how to check your credit score. If youre a user of Ahrefs, we have a cool SERP Checker tool within Keywords Explorer, where we pull top10 ranking pages for your keyword and show you how much traffic they get in total (along with many other useful metrics):
I know it is tempting to assume that search volume of a keyword and total traffic of the top ranking pages are highly correlated, but were now running a study that proves otherwise:
But Im going to publish the results of this study as a separate post, once we finish it and doublecheck our numbers.
Final words Google gets better and better each year at understanding all sorts of peculiar search queries that people put into it. This means that the long tail of search is getting even longer and the search volume of an individual keyword is becoming more and more obsolete. So if youre not already building your SEO strategy around topics instead of keywords, it is about time to adopt this new mindset. https://ahrefs.com/blog/keyword-search-volume/