The following limits apply when using the Microsoft Translator Text API:
Request size: 5000 characters.
You are charged per character, not per request, so you may as well use shorter requests and have multiple requests outstanding. Learn more about how Microsoft Translator counts characters.
Number of outstanding requests to the Translator service: unlimited.
Be sure to always pass complete sentences to the API. As noted above, you are charged per character, not per request, so you may as well use shorter requests and have multiple requests outstanding.
Number of characters per hour:
The volume of characters per hour is based on the Microsoft Translator Text API subscription tier you are subscribed to in the Azure portal. This is not a guarantee that you can achieve these limits, but you are likely to receive an out of quota response if you reach these limits:
F0 tier: 2 million characters
S1 and S2 tiers: 40 million characters
S3 tier: 120 million characters
S4 tier: 200 million characters
The above applies to the Microsoft-provided generic systems. The limits apply per Microsoft Translator Text API subscription. The same limits apply per originating IP.
Custom systems using the Microsoft Translator Hub are further limited to 1800 characters per second.
Latency: 13 seconds.
Microsoft Translator has a maximum latency of 13 seconds. At that time you will have received the result or a timeout response. The typical response time for a short request is 150 to 300 milliseconds. The typical response time varies per request size and per language pair.
Sentence Length: maximum sentence length is 275 characters, with the following exceptions:
This means that the Breaksentences function will always return sentence below this number. You can still translate longer sentences.
Last update: April 10, 2018