Guidelines and Quotas

Many of the Amazon Comprehend quotas shown here can be increased if needed for your applications. For information about service quotas and to request a quota increase, see AWS Service Quotas .

Keep in mind the following information when using Amazon Comprehend.

Supported Regions

For a list of AWS Regions where Amazon Comprehend is available, see AWS Regions and Endpoints in the Amazon Web Services General Reference.

Overall Quotas

All operations except asynchronous operations and topic modeling operations have the following quotas:

Description	Quota/Guideline
Character encoding	UTF-8
Document size (UTF-8 characters)	5,000 bytes

Amazon Comprehend may store your content to continuously improve the quality of its analysis models. See the Amazon Comprehend FAQ to learn more. To request that we delete content that may have been stored by Amazon Comprehend, open a case with AWS Support.

Throttling When Using Single Transactions

You may be able to avoid throttling by using the batch operations instead of the single transaction operations. For more information, see Multiple Document Operations.

Multiple Document Operations

The BatchDetectDominantLanguage, BatchDetectEntities, BatchDetectKeyPhrases, and BatchDetectSentiment operations have the following quotas:

Description	Limit
Documents per request	25

If you plan to send more than 20 requests per second, you should consider using the batch operations. Batch operations enable you to send more documents in each request which may result in higher throughput. For example, when you use the DetectDominantLanguage operation, you can send up to 20 documents per second. However, if you use the BatchRequestDominantLanguage operation, you can send up to 250 documents per second, but processing speed may be lower. For more information about throttling quotas see Amazon Comprehend Quotas in the Amazon Web Services General Reference. For more information about using the multiple document APIs, see Multiple Document Synchronous Processing.

Asynchronous Operations

Asynchronous batches started with the StartDominantLanguageDetectionJob, StartEntitiesDetectionJob, StartKeyPhrasesDetectionJob, and StartSentimentDetectionJob have the following limits:

Description	Quota/Guideline
Maximum size (UTF-8 characters) for one document, entity and key phrase detection	100 KB
Maximum size (UTF-8 characters) for one document, language detection	1 MB
Maximum size (UTF-8 characters) for one document, sentiment detection	5 KB
Total size of all files in batch	5 GB
Maximum number of files, one document per file	1,000,000

You should use the asynchronous operations:

• To analyze more than 25 documents at a time

• To analyze documents larger than 5,000 bytes for keywords and entities

For more information, see Asynchronous Batch Processing.

Document Classification

Document classifier training jobs started with the CreateDocumentClassifier operation, asynchronous document classification jobs started with the StartDocumentClassificationJob operation, and synchronous document classification requests started with the ClassifyDocument operation have the following limits:

Description	Quota/Guideline
Character encoding	UTF-8
Maximum number of classes (multi-class mode)	1,000
Maximum number of classes (multi-label mode)	100
Maximum length of class name	5,000 characters
Minimum number of training documents per class (multi-class mode)	50
Minimum number of training documents per class, (multi-label mode)	10
Total size of all files in training job	5 GB
Total size of all files in asynchronous job	5 GB
Maximum file size for one file, one document per file	10 MB
Maximum number of files, one document per file	1,000,000
Maximum number of lines, one document per line (for all files in request)	1,000,000
Maximum number of documents per synchronous request	1
Maximum number of inference units per account	10
Maximum number of inference units per endpoint	10
Maximum throughput per inference unit (characters)	100/second
Maximum throughput per inference unit (documents)	2/second

Language Detection

The BatchDetectDominantLanguage, DetectDominantLanguage operations and asynchronous jobs started with the StartDominantLanguageDetectionJob operation have the following limitations:

• They don't support phonetic language detection. For example, they will not detect "arigato" as Japanese nor "nihao" as Chinese.

• They may have trouble distinguishing close language pairs, such as Indonesian and Malay; or Bosnian, Croatian, and Serbian.

• For best results the input text should be at least 20 characters long.

Topic Modeling

Topic detection jobs created with the StartTopicsDetectionJob operation have the following limits:

Description	Quota/Guideline
Character encoding	UTF-8
Maximum number of topics to return	100
Maximum total size of all files in request	5 GB
Minimum total size of all files in request	500 bytes
Maximum file size for one file, one document per file	100 MB
Maximum number of files, one document per file	1,000,000
Maximum number of lines, one document per line (for all files in request)	1,000,000

For best results, you should include at least 1,000 input documents.

Custom Entity Recognition

Custom entity recognition jobs started with the CreateEntityRecognizer operation have the following limits:

General
Description	Minimum	Maximum
Number of entities per model/custom entity recognizer	1	12
Document size (UTF-8)	1 byte	5,000
Number of documents	1,000	120,000
Document corpus size (all docs in plain text combined)	5 KB	100 MB

Annotations
Description	Minimum	Maximum
Number of annotations per entity	200	n/a

Entity Lists
Description	Minimum	Maximum
Number of items in entity list	1	1,000,000
Length of individual entry (post-strip) in entry list	1	5,000
Entity list corpus size (all docs in plain text combined)	5 KB	100 MB