Domain Analytics Whois API

Domain Analytics Whois API will provide you with Whois records and essential SERP data on millions of domains across the web.

Domain Analytics Whois API¬† is based on DataForSEO’s proprietary database and therefore natively supports the Live mode of data processing.
Using this API, your account will be billed for both setting a task and retrieving its results.

See docs
Domain Analytics Whois API

Live mode, turnaround time - up to 2 seconds on average
$0.1

per task

$0.001

per item

$1,100
for 1M domains*

*Price Calculation

The number of domains you can get in a single response is limited to 1,000, so you will have to make 1,000 requests in order to obtain 1M domains and related data.

Given that the price for setting a task is $0.1 and the price per each item is $0.001, the price for 1M domains is calculated as follows:

1,000*0.1 + 1,000,000*0.001 = $1,100