Data and rate limits for the Text Analytics API

Use this article to find the limits for the size, and rates that you can send data to Text Analytics API. Note that pricing is not affected by the data limits or rate limits. Pricing is subject to your Text Analytics resource's pricing details.

Data limits


  • If you need to analyze larger documents than the limit allows, you can break the text into smaller chunks of text before sending them to the API.
  • A document is a single string of text characters.
Limit Value
Maximum size of a single document 5,120 characters as measured by StringInfo.LengthInTextElements. Also applies to Text Analytics for health.
Maximum size of a single document (/analyze endpoint) 125K characters as measured by StringInfo.LengthInTextElements. Does not apply to Text Analytics for health.
Maximum size of entire request 1 MB. Also applies to Text Analytics for health.

If a document exceeds the character limit, the API will behave differently depending on the endpoint you're using:

  • /analyze endpoint:
    • The API will reject the entire request and return a 400 bad request error if any document within it exceeds the maximum size.
  • All other endpoints:
    • The API won't process a document that exceeds the maximum size, and will return an invalid document error for it. If an API request has multiple documents, the API will continue processing them if they are within the character limit.

The maximum number of documents you can send in a single request will depend on the API version and feature you're using, which is described in the table below.

The following limits are for the current v3 API. Exceeding the limits below will generate an HTTP 400 error code.

Feature Max Documents Per Request
Language Detection 1000
Sentiment Analysis 10
Opinion Mining 10
Key Phrase Extraction 10
Named Entity Recognition 5
Entity Linking 5
Text Analytics for health 10 for the web-based API, 1000 for the container.
Analyze endpoint 25 for all operations.

Rate limits

Your rate limit will vary with your pricing tier. These limits are the same for both versions of the API. These rate limits don't apply to the Text Analytics for health container, which does not have a set rate limit.

Tier Requests per second Requests per minute
S / Multi-service 1000 1000
S0 / F0 100 300
S1 200 300
S2 300 300
S3 500 500
S4 1000 1000

Requests rates are measured for each Text Analytics feature separately. You can send the maximum number of requests for your pricing tier to each feature, at the same time. For example, if you're in the S tier and send 1000 requests at once, you wouldn't be able to send another request for 59 seconds.

See also