With Amazon Comprehend, you only pay for what you use. You are charged based on the amount of text processed on a monthly basis. Amazon Comprehend provides natural language processing, topic modeling, and Custom Classification capabilities, enabling a broad range of applications that can analyze text.   

  • Natural Language Processing: Amazon Comprehend requests for Entity Recognition, Sentiment Analysis, Syntax Analysis, Key Phrase Extraction, and Language Detection are measured in units of 100 characters, with a 3 unit (300 character) minimum charge per request.
  • Topic Modeling: Topic Modeling identifies relevant terms or topics from a collection of documents stored in Amazon S3. It will identify the most common topics in the collection and organize them in groups and then map which documents belong to which topic. You are charged based on the total size of documents processed per job. The first 100 MB is charged a flat rate. Above 100 MB, you are charged per MB.
  • Custom Comprehend: The Custom Classification and Entities APIs can train a custom NLP model to categorize text and extract custom entities. Inference requests are measured in units of 100 characters, with a 3 unit (300 character) minimum charge per request. You are charged $3 per hour for model training (billed by the second) and $0.50 per month for custom model management.
Price Per Unit
Feature Up to 10M units From 10M -  50 units Over 50M units
Key Phrase Extraction $0.0001 $0.00005 $0.000025
Sentiment Analysis $0.0001 $0.00005 $0.000025
Entity Recognition $0.0001 $0.00005 $0.000025
Language Detection $0.0001 $0.00005 $0.000025
Syntax Analysis $0.00005 $0.000025 $0.0000125

NLP requests are measured in units of 100 characters, with a 3 unit (300 character) minimum charge per request.

Custom Comprehend

Custom Entities & Classification
$0.0005 per unit

Inference requests are measured in units of 100 characters, with a 3 unit (300 character) minimum charge per request.

$3 per Hour for Model Training
$0.50 per Month for Custom Model Management
Topic Modeling

$1.00 (flat rate) per job

For the first 100MB

$0.004 per MB

For every MB above 100MB

You are charged based on the total size of documents processed per topic modeling job. The first 100 MB is charged a flat rate. Above 100 MB, you are charged per MB.

Free Tier

50K units of text (5M characters)

For each of the 7 APIs (Key Phrase Extraction, Sentiment Analysis, Entity Recognition, Language Detection, Syntax Analysis, Custom Entities, and Custom Classification) per month, starting from the date of your first Amazon Comprehend request.

For the Custom Classification and Custom Entities APIs, there is no free tier for model training and custom model management.

5 jobs up to 1MB each

The Amazon Comprehend free tier is available to both new and existing AWS customers for 12 months, starting from the date of their first Amazon Comprehend request.

Amazon Comprehend Medical Pricing

With Amazon Comprehend Medical, you pay only for what you use. You are charged based on the amount of text processed on a monthly basis. Amazon Comprehend Medical provides two APIs: Medical Named Entity and Relationship Extraction (NERe) and Protected Health Information Data Extraction and Identification (PHId).

The Medical NERe API extracts entities, entity relationships, entity traits, and PHI. If customers want to only identify PHI for data protection, they can request the PHId API. All API requests are measured in units of 100 characters, with one unit (100 characters) minimum charge per request.

Feature Price per unit
Medical Named Entity and Relationship Extraction (NERe) API $0.01
Medical Protected Health Information Data Extraction and Identification (PHId) API $0.0014

Amazon Comprehend Medical Free Tier

Amazon Comprehend Medical offers a free tier covering 25k units of text (2.5M characters) for the first three months when you start using the service for both the Medical Named Entity and Relationship Extraction (NERe) API and the Protected Health Information Data Extraction and Identification (PHId) API.

Amazon Comprehend pricing examples

Example 1 - Analyzing Customer Comments

Let us assume you have built an application using Amazon Comprehend to analyze customer comments on your online store. You have received 10,000 customer comments that are 550 characters each, and you are in the second year of your use of the service.

Total charge calculation:

Size of each request = 550 characters

Number of units per request = 6

Total Units: 10,000 (requests) x 6 (units per request) = 60,000

Price per unit = $0.0001

Total cost = [No. of units] x [Cost per unit] = 60,000 x $0.0001 = $6.00


Example 2 - Categorizing Documents by Topics

Let us say you have a set of research documents totaling 240 MB in size that you want to categorize by topic and recommend documents to your customers based on their area of interest. Let us also assume that you are in the second year of your use of the service and are not eligible for the free tier offering.

Total charge calculation:

Total megabytes processed = 240

Megabytes billed at a flat rate of $1 = 100

Megabytes billed at $0.004/MB = 140 [240-100]

Total cost of the job = $1.00 + [140 x $0.004] = $1.00 + $0.56 = $1.56


Example 3 - Classifying Customer Feedback using the Custom Classification API

Let us say you want to train a classifier to automatically organize new customer feedback that comes in from your website. You have 3,000 characters that you want to include in your custom model. It takes one hour to train the custom model, and you are planning to keep this model for a month. Let us also assume that you are in the second year of your use of the service and are not eligible for the free tier offering.

Total charge calculation:

Size of each request = 3,000 characters

Number of units per request = 30 units [3,000 characters ÷ 100 character per unit]

Price per unit = $0.0005

Total cost for units = $0.015 [30 units x $0.0005]

Total hours  for model training = 1 hour

Price per hour = $3

Total cost for model training = $3 [1 hour x $3]

Number of months for model management = 1 month

Price per month = $0.50 

Total cost for model managment = $0.50 [1 month x $0.50]

Total cost = $3.515 [$0.015 + $3 + $0.50]


Example 4 - Extracting Medical Entities from Clinical Documents

Let us assume you have built an application using Amazon Comprehend Medical to analyze clinical documents in your data lake. You have 1,000 clinical documents that are 2,550 characters each. Let us also assume that you are in the second year of your use of the service and are not eligible for the free tier offering.

Total charge calculation:

Size of each request = 2,550 characters

Number of units per request = 26 units [2,550 characters ÷ 100 character per unit]

Total Units: 1,000 (requests) x 26 (units per request) = 26,000

Price per unit = $0.01

Total cost = [No. of units] x [Cost per unit] = 26,000 x $0.01 = $260.00


Example 5 - Analyzing Customer Comments using the Custom Entities API

Let us say you want to train a custom entity model to automatically extract custom terms from customer feedback that comes in from your website. The training job takes 1.5 hours, and you analyze 10,000 pieces of customer feedback that are 550 characters each. You are planning to keep this model for a month. Let us also assume that you are in the second year of your use of the service and are not eligible for the free tier offering.

Total charge calculation:

Size of each request = 5,500,000 characters

Number of units per request = 55,000 units [5,500,000 characters ÷ 100 character per unit]

Price per unit = $0.0005

Total cost for units = $27.5 [55,000 units x $0.0005]

Total hours  for model training = 1.5 hours

Price per hour = $4.5

Total cost for model training = $3 [1.5 hours x $3]

Number of months for model management = 1 month

Price per month = $0.50 

Total cost for model managment = $0.50 [1 month x $0.50]

Total cost = $37 [$27.5 + $4.5 + $0.50]

Learn more about Amazon Comprehend features

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