Amazon Comprehend pricing calculator
NLP, PII, Topic Modeling & Custom Models. Estimate your costs using AWS list prices.
Estimates from AWS list prices, not an AWS quote. Discounts, taxes and credit terms may affect your bill.
01 · How Amazon Comprehend pricing works
What you pay for
- Built-in text APIs per unit of 100 characters with a 3-unit (300-character) minimum per request, tiered by monthly volume ($0.0001 per unit for the first 10 M on most APIs).
- PII detection and redaction per unit; ContainsPiiEntities and syntax are cheaper.
- Custom classification and entity recognition: training per hour, model storage per month, real-time endpoints per inference unit per second, async per unit.
Common cost traps
- The 3-unit minimum makes very short texts (tweets, labels) cost as much as 300 characters.
- Custom endpoints bill per second while provisioned, even with no traffic.
- Running several APIs on the same text bills each API separately.
Ways to reduce cost
- Batch short texts into documents with async jobs where latency allows.
- Delete custom endpoints when idle or use async jobs instead.
- For many NLP tasks, compare a small Bedrock model with one prompt doing several analyses at once.
Free Tier & account eligibility
Free Tier depends on account age. Accounts created on or after 15 July 2025 get a $100 sign-up credit plus up to $100 more for completing onboarding activities; on the Free plan these last 6 months (or until used up), on the Paid plan unused Free Tier credits stay usable for 12 months from sign-up. Accounts created before 15 July 2025 keep the legacy Free Tier (12-month offers plus always-free offers). Always-free offers apply on both plans. Legacy accounts: 50,000 units (5 M characters) per API per month for 12 months, plus limited custom model allowances. New-plan accounts pay from Free Tier credits.
02 · AWS credits & runway
Do credits cover Amazon Comprehend?
Comprehend text API units, PII detection, custom classification/entity training and endpoints, and async jobs are eligible usage and are offset by credits. General rules: credits only offset charges from the billing cycle in which they were applied onward (never past bills), they apply only to the services listed on the credit in Billing and Cost Management > Credits, they expire on the date shown there, and accounts on the AWS Free plan cannot receive Activate credits until they upgrade to the Paid plan.
Check my creditsExcluded charges & conditions
- Upfront payments for Savings Plans and Reserved Instances (All Upfront, and the upfront part of Partial Upfront). The recurring hourly fee of a No Upfront commitment is billed as normal usage and can be offset.
- AWS Marketplace charges (Activate credits make an exception for third-party foundation models used through Amazon Bedrock).
- AWS Enterprise Support, Enterprise On-Ramp, Unified Operations, resold support and partner-led support.
- Amazon Route 53 domain name registration and transfer fees.
- Taxes (sales, use, VAT and similar), AWS Professional Services, Training and Certification, Mechanical Turk, AWS Managed Services, and any use for cryptocurrency mining.
Illustrative credit runway
Single-service examples from the supplied data, not your calculator result. Months = credit amount ÷ monthly cost, before credit expiry. Credits can expire before these theoretical months are used; coverage and other AWS services can shorten runway.
| Usage profile | Monthly estimate | $10,000 | $25,000 | $100,000 |
|---|---|---|---|---|
| Small | $120.00 | 83.3 mo. | 208.3 mo. | 833.3 mo. |
| Medium | $1,700.00 | 5.9 mo. | 14.7 mo. | 58.8 mo. |
| Large | $8,000.00 | 1.3 mo. | 3.1 mo. | 12.5 mo. |
Small profile assumptions
Sentiment and entities on 200,000 short reviews (300 characters each = 3 units per API) | Sentiment units: 600,000 units x $0.0001 = $60.00; Entity units: 600,000 units x $0.0001 = $60.00 | Total ~$120.00/month, us-east-1 on-demand list prices, before Free Tier, taxes and support.
Medium profile assumptions
5 M units each of sentiment, entities and key phrases, plus 2 M PII detection units | Sentiment units: 5,000,000 units x $0.0001 = $500.00; Entity units: 5,000,000 units x $0.0001 = $500.00; Key phrase units: 5,000,000 units x $0.0001 = $500.00; PII detection units: 2,000,000 units x $0.0001 = $200.00 | Total ~$1,700.00/month, us-east-1 on-demand list prices, before Free Tier, taxes and support.
Large profile assumptions
60 M units each of sentiment and entities (tiered), 20 M PII units | Sentiment units: 60,000,000 units tiered (10,000,000 @ $0.0001; 40,000,000 @ $0.00005; 10,000,000 @ $0.000025) = $3,250.00; Entity units: 60,000,000 units tiered (10,000,000 @ $0.0001; 40,000,000 @ $0.00005; 10,000,000 @ $0.000025) = $3,250.00; PII detection units: 20,000,000 units tiered (10,000,000 @ $0.0001; 10,000,000 @ $0.00005) = $1,500.00 | Total ~$8,000.00/month, us-east-1 on-demand list prices, before Free Tier, taxes and support.
04 · Questions
Amazon Comprehend pricing FAQ
How is text measured?
In units of 100 characters, with a minimum of 3 units (300 characters) per request.
Is PII detection priced separately?
Yes. DetectPiiEntities is priced like other text APIs; ContainsPiiEntities is much cheaper ($0.000002 per unit here).
Do custom endpoints cost when idle?
Yes, they bill per inference unit per second while provisioned.
Do credits cover Comprehend?
Yes, it is eligible usage.
05 · Sources & estimate notes
Content pack dated 2026-10-19. Calculator rates remain their existing snapshots; this content update is not a price refresh.
Verification notes
- Runway prices come from the calculator repository snapshot rate card comprehend (no AWS Price List mapping in the build). Confirm the main unit prices on https://aws.amazon.com/comprehend/pricing/ before publishing.