API Limits and Restrictions
To ensure the continuous operation of SE Ranking’s API for all clients, we limit the speed of sending queries. Any API method can be invoked no more than 10 time per second.
For example, if a client application makes more than 10 query per second, the server will return the 429 error code and a message that the application needs to slow down.
If users repeatedly go over the limit on the number of possible queries per second, they will have limited access to the API for 10 minutes. Should the limit be exceeded again in the future, the blocking time will increase.
The Competitor Research and Keywords Research APIs allow sending 1 request per second (while for other tools, it is 10 requests per second).