Our service is subject to FUP (Fair Use Policy), as defined in our Service level agreement, in order to prevent massive overloading by individual users at the cost of others. The FUP limit applies to the number of requests (not to the volume of data transferred) per one minute, one hour and one day and defaulting to 100, 900 and 2,000 requests, respectively. Further requests will be denied automatically upon exceeding any of these limits. Applying FUP does not constitute a violation and Lexical Computing, the company behind Sketch Engine, reserves the right to take measures to prevent customers violating the FUP from using the service.

You may be affected by it in two ways:

In the web interface

When working very intensively in the interface, you may occasionally exceed our limits. You are then asked to complete a CAPTCHA test to prove you are human to continue your work. We are sorry for these false alarms and the inconvenience they bring. We regularly analyze them and adjust our settings to minimize them.

While using our API

You are expected to stay within the FUP limits. When you exceed them, our servers will respond to your requests with the HTTP status code 429 Too many requests. You should respond by stopping further requests, especially as they would fail anyway and put unnecessary load on our servers. It is advisable to insert a wait time between requests if you suspect the FUP could be reached.

  • For fewer than 100 requests, you may not need to wait at all.
  • For 100–900 requests, we recommend 4 seconds.
  • For more than 900 requests, it is best to wait at least 45 seconds.

If you accidentally hit our limits when testing your code, it is acceptable to use the CAPTCHA test once or twice to reset your numbers. However, doing so regularly is considered cheating and frowned upon. The same applies to creating multiple trial accounts to “stack” their limits. Prolonged frowning from our side may result in your network getting blocked.