Languages and names are fluid and change over time. From customer to customer, data sets also vary a lot in quality, scope and origin. Therefore, we cannot guarantee that all results you receive from our API are 100% correct and match your data pool. But we can promise that we are always committed to providing you with the best results possible and that we regularly improve and update our algorithms. We also add new data on a very regular basis. You can find out more about our updates here. In the unlikely event of our service not matching up with your expectations, we give you a straightforward 14-day money-back guarantee. Of course, we also offer to test our service completely free of charge. If you sign up here, you will receive 100 requests for free every month. If you query a name, our endpoints will either return an accuracy or a probability value in the response, depending on your API version. The accuracy parameter returns how sure we are that this name is either male or female. The value is calculated by the number of records for this in our database. Since use cases differ significantly, we do not give any recommendations on the level of accuracy. Depending on your use case, it is up to you to decide what results and accuracy levels to accept. Even with an accuracy of at least 99%, there is a possibility that the result is incorrect. However, a value above 95% fits most use cases in general.