Here are some best practices when using the 'Translate' request in KantanMT API:
What is the optimal segment length?
Translation quality is optimal when segments are no longer than one fully qualified sentence. Longer segments will still be translated but sometimes the quality (fluency) will be slightly worse but the main reason is the processing efficiency will be reduced.
How many segments should I send per request?
One segment per request is best.
Is there a limit to how many segments you can send per request?
There is no upper limit per se. As long as the HTTP request stays open you could, in theory, send as many as you want. However, the recommended limit, if you want to send multiple segments per request, is 10 segments per request.
How many requests can you send in parallel?
If you are sending multiple requests at once, 6 is the maximum recommended number of requests to send in parallel. Any more than this and you run the risk of segment requests timing out.