IndustryComparing keyword research APIs: Spyfu vs SEMRush vs Serpstat and more

Comparing keyword research APIs: Spyfu vs SEMRush vs Serpstat and more

Many tools provide access to their APIs, aiming to facilitate routine work for specialists.

APIs can make SEOs’ lives much easier by helping to:

  • Data mine and extract keywords faster
  • Collect the necessary data directly to an external service or program (i.e. Google Spreadsheets, Cyfe, etc.)
  • Perform advanced search term research via XML or Excel
  • Integrate all kinds of data from different sources (i.e. rankings and backlinks)
  • Create complex reports combining all kinds of data
  • Automate reporting
  • Build and market your own tools
  • Create internal tools to optimize your team workflow, etc.

While we all have our favorite SEO tools we use on a daily basis, APIs give us the flexibility no tool can provide by letting us grab the data we need and sort / filter it the way our SEO tasks require.

I’m constantly working with keyword research tools and I have had the opportunity to give many APIs a try. So I decided to carry out a small study comparing the keyword research APIs I have looked into, and share my research in a blog post.

I took the best-known SEO tools which provide APIs for working with keywords and analyzed how much it will cost to make a call for 1,000,000 units.

All-in-one SEO dashboards


SpyFu is a platform for SEO and PPC specialists focusing on competitor analysis and keyword tracking. Spyfu is one of the oldest keyword research tools I am aware of — which means its database is actually huge, storing years of data.

SpyFu offers three subscription levels: Basic – $49, Professional – $99, Team – $299. An API is included into subscriptions starting from Professional level.

All of the subscriptions with an API come with 10,000 API rows/units returned a month. Every additional 1,000 units are charged at $0.50. Hence 1,000,000 units would be $495 additional in charges.

So the final price for 1,000,000 is $594.

Maybe you’ll be glad to hear that SpyFu does not put any limits on the number of requests.

Spyfu API documentation is here.

To summarize, to get 1,000,000 results via API you’ll have to buy a plan worth $99 and pay $495 more for 990.000 API units.


SEMrush offers analysis of organic traffic and paid ads, backlinks, and keywords. SEMrush was the first keyword research tool I ever used. I love their data output.

The tool includes three subscription levels starting at $99.95, but an API is only included into Business tariff worth $399.95.

Screencap of the three subscription options offered by SEMRush: Pro, at $99.95 per month, Guru, at $199.95 per month, and Business at $399.95 per month.

But that’s not all. API units are not included into the plan, so you have to purchase them additionally. 20,000 API units cost $1, so to process 1,000,000, you need to pay $50.

So with SEMrush you have to pay $449.95 for 1,000,000 of API requests. There are no daily limits.

SEMrush API documentation is located here. To summarize, to get 1,000,000 results via API you’ll have to buy a subscription ($399) and pay $50 to use enough API units.


Serpstat is an all-in-one platform for SEO and PPC specialists providing keyword research and tracking tools as well as on-site analysis and backlink tracking.

It includes eight paid plans of different limitations from $19 to $2500.

An API is enabled starting from Plan B which costs $69. As I didn’t exactly understand the API conditions, I sent a letter to Serpstat support as well.

Turns out Serpstat provides access to API separately from their subscription plans. So you can use the API without actually upgrading to PRO:

So with Serpstat you can get 1,000,000 units for $150.

Serpstat API documentation is located here. Short summary: 1,000,000 units cost $150 without any additional payments.

Pure keyword research tools


Wordtracker is a solid keyword research solution with a huge database. They claim to operate the database of 3.5 billion search terms (350 million unique keywords) these days.

Their API comes in their Gold subscription level, but to have more flexibility with the API you’ll likely to have to purchase one of the API-only packages. Besides, Wordtracker API access is subject to approval from their team, so it sounds like they may not accept some applications.

If their API packages seem confusing to you, you are not alone. I had to contact them to confirm what I need to buy to get 1,000,000 units. From their reply it sounds like the “Enterprise” plan will be enough.

Each call is priced for 100 seeds, so for 1, 000,000 terms you’d need 10,000 calls. A simple volume search is priced at 10 units per call so you’d be using 100,000 units.

Wordtracker API documentation is here. is a keyword selection tool that uses autosuggest results from Google, YouTube, Bing, Amazon, and Apple App Store. includes a free limited version and three types of paid subscription levels. The API is available separately from the paid subscriptions and it’s priced as follows:

As you can see in the image above, API includes three subscription plans of different limitations and prices, starting from $280/month.

Looks like their API Lite plan handles the amount of keywords we need. So, for $280 you can handle 1,000,000. Note that you can make only 100 requests per day, so it will take 13 days to conduct the full amount of work. If you need it quicker, you’ll have to purchase a more expensive plan. API documentation is available here.

Short summary: 1,000,000 API units are available in the API Lite Plan which is worth $280.

More APIs

I haven’t included a few APIs in my research, so here they are:

  • Raven Tools: I was told API wasn’t their priority at this time. They focus on their Audit tool instead.
  • Keyword Discovery: They seem to have a good API but I couldn’t figure out how to get 100,000 units there. They charge $495 per month per 10,000 queries and it seems impossible to buy more units.
  • Wordstream: They have retired their API altogether.

The Bottom Line

Advanced professionals who have a lot of projects, and little time, always choose an API for their professional needs. I hope this little research of mine will help you pick a suitable keyword research API:

# Of Units Daily Calls Price
Spyfu 1,000,000 units No limits $594
SEMrush No limits $449.95
Serpstat No limits $150
WordTracker No limits $1,000 100 requests $280

I cannot comment on the quality of the databases, to be honest. I have been using each of the above tools and I find it great that they all present the information differently. That lets me find what I failed to with other tools. That being said, the more keyword research offered, the better.

Update: In response to this article Spyfu lowered their API pricing. For the current Premium customers the price is adjusted automatically. The article above has been updated to reflect the change. We are making the web better one post at a time 🙂


Screenshots by Ann Smarty. Taken February 2017. Featured Image: johnhain / pixabay


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