Optimize your ad campaigns
and write better content

With keyword.io PRO, you get:

English Keywords semantically related to your topic More

Our free longtail keyword tools do an awesome job in finding keywords for you that are narrowed down versions of your seed keyword.

What they can not do though is actually understand the concepts and topics behind it, finding synonyms and related questions or products.

Hundreds of millions of data points allow us to draw connections and give you related keywords for your query!

Up to 20,000 keywords per seed More

We have 214+ million and counting keywords in our database that fuel your results.

Unlike Adwords Keyword Tool, we have no motivation to hide keywords from you. You get all useful information we can give you.

Depending on your seed keyword, you get up to 20,000 related keywords.
Have a look at our examples below to see what that looks like.

Search Volume, CPC and Competition from Adwords More

All the data you know and love, regularily updated for global, english searches.

Sort by any metric and see get an instant overview of the pricing and competition distribution for sub-niches of your topic.

Results in your browser, spreadsheet or by API More

Use our related keywords tool in your browser, download CSV for easy spreadsheet import or access the data by API.

No matter how you want to work, we support it all, one price.

Smart filters and aggregations More

Filter by terms and even topics and metrics with a few clicks! You can see how expensive and competitive sub-topics are with a single glance.

The difference between our free and PRO tool's data

Longtail keyword tools only find expansions of the seed keyword. Our related keywords tool goes way beyond that into the realms of pure magic.
It gets you semantically related keywords by leveraging hundreds of millions of data points in more than 93 millions (and counting) english keywords and enriches them with up to date search volume and more.

This is the difference for the seed keyword wordpress:

Keyword Confidence Searches CPC Competition
FREE wordpress 100% 2,740,000 $0.77 0.11
wordpress plugin 100% 60,500 $2.02 0.04
best free wordpress themes 100% 9,900 $1.16 0.03
683 more keywords …
PRO seo wp theme 91% 720 $4.31 0.21
yoast seo 89% 12,100 $6.60 0.18
premium themes 87% 590 $0.27 0.31
19,643 more keywords …

What is our "related keyword tool" about?

Free longtail keywords

Let's say you work with a keyword like car insurance.
You'd probably work with longtail keywords like the one to the right.

This list has some awesome keywords and you can find thousands of them with our free longtail keywords tool or with our API once you subscribe.

But they only show you a vertical segment of your topic – keywords that include your seed keyword.

Longtail keywords

  • cheap car insurance
  • car insurance comparison
  • car insurance for new car
  • best car insurance
  • best car insurance in seattle
  • how much is a car insurance in seattle
  • … and hundreds more of those

Our related keywords tool

The second list shows you some of the thousands of english keywords our new related keywords tool has found. They are all relevant for car insurance, but cover the topic from very different angles, finding synonyms and common use cases for car insurances.

Of course you can filter these keywords by terms and topics and sort them by any criteria you can think of – search volume, price, number of terms, degree of relatedness to your seed keyword, …

keyword.io's new related keywords

  • auto insurance
  • progressive auto insurance quote
  • cheapest breakdown cover
  • hail damage repair
  • how to find out if a car is stolen
  • car accident liability
  • … and 14,436 more of those

Does this sound useful to you?

See plans

  • Get a big edge on your competitors
  • Promotional offer – save up to $30 per month
  • Test risk free for $5 for a whole day with full functionality!

Choose a plan

Pro Personal Free

Related Keywords

This is pure magic! Find english keywords that are semantically related.

"keyword research" also finds terms like "adword tools" or "seo software" to give you an idea.

Works with our web tool and API

Related Keywords Tool
Up to 20,000 Keywords per Seed
Monthly Searches
CPC/Competition on Google Ads
Stats lookup tool and API
API Access
Usage Quoata 1000 / day 2 100 / day 3

Longtail Keywords

Find phrases and questions you would never be able to think of yourself.
From Google, Amazon, Youtube and many more

Access 11 different Sources
Hundreds of Keywords per Seed
Unlimited Access to Online Tool
Download Keywords
Copy Keywords to clipboard
API Access (100 / day)

$79 $49/month 1

This plan is currently unavailable :(

$39 $29/month 1

This plan is currently unavailable :(


1 You can always end your contract to the end of your billing period, just send us an email.

2 Limited to 10 requests per minute and 1000 requests per day for either web and API access. Need more? Contact us!

3 Limited to 5 requests per minute and 100 requests per day for either web or API access

Our order process is conducted by our online reseller Paddle.com. Paddle.com is the Merchant of Record for all our orders. Paddle provides all customer service inquiries and handles returns.

What it looks like

Keyword.io PRO Screenshot
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Looking for a custom solution?

Many tool suppliers rely on our PRO APIs as well as custom built endpoints and datasets.

We have the data, the expertise and the infrastructure to gather and make sense of billions of datapoints to give you the tools to help your business and your customers.

You want to leverage this for your business? Let's talk!


api Created with Sketch.

API Documentation

You can use our API with our PRO plan and get longtail keywords and related keywords with search volume and CPC prices automatically!

Find our keyword.io API documentation here.


Don't hestitate to contact us with any question at