Request limits for Translator Text

This article provides throttling limits for the Translator Text API. Services include translation, transliteration, sentence length detection, language detection, and alternate translations.

Character and array limits per request

Each Translate request is limited to 5,000 characters. You're charged per character, not by the number of requests. It's recommended to send shorter requests.

The following table lists array element and character limits for each operation of the Translator Text API.

Operation Maximum Size of Array Element Maximum Number of Array Elements Maximum Request Size (characters)
Translate 5,000 100 5,000
Transliterate 5,000 10 5,000
Detect 10,000 100 50,000
BreakSentence 10,000 100 50,000
Dictionary Lookup 100 10 1,000
Dictionary Examples 100 for text and 100 for translation (200 total) 10 2,000

Character limits per hour

Your character limit per hour is based on your Translator Text subscription tier.

The hourly quota should be consumed evenly throughout the hour. For example, at the F0 tier limit of 2 million characters per hour, characters should be consumed no faster than roughly 33,300 characters per minute sliding window (2 million characters divided by 60 minutes).

If you reach or surpass these limits, or send too large of a portion of the quota in a short period of time, you'll likely receive an out of quota response. There are no limits on concurrent requests.

Tier Character limit
F0 2 million characters per hour
S1 40 million characters per hour
S2 / C2 40 million characters per hour
S3 / C3 120 million characters per hour
S4 / C4 200 million characters per hour

Limits for multi-service subscriptions are the same as the S1 tier.

These limits are restricted to Microsoft's standard translation models. Custom translation models that use Custom Translator are limited to 1,800 characters per second.

Latency

The Translator Text API has a maximum latency of 15 seconds using standard models. Translation using custom models has a maximum latency of 25 seconds. By this time you'll have received a result or a timeout response. Typically, responses are returned in 150 milliseconds to 300 milliseconds. Response times will vary based on the size of the request and language pair. If you don’t receive a translation or an error response within that timeframe, you should check your network connection and retry.

Sentence length limits

When using the BreakSentence function, sentence length is limited to 275 characters. There are exceptions for these languages:

Language Code Character limit
Chinese zh 132
German de 290
Italian it 280
Japanese ja 150
Portuguese pt 290
Spanish es 280
Italian it 280
Thai th 258

Note

This limit doesn't apply to translations.

Next steps