# Amazon Comprehend vs NLTK

| Attribute | Amazon Comprehend | NLTK |
|---|---|---|
| **Vioscale score** | 72.3 (33% (low)) | 72.7 (21% (low)) |
| activity.commits_last_30d | - | 100 |
| adoption.dependent_repos | - | 57,572 |
| adoption.github_stars | - | 14,702 |
| deployment.options | `{"cloud":true}` | - |
| description.long | A machine learning service that processes text to identify entities, sentiment, topics, and key phrases. It supports both standard pre-built models and custom models trained on your own data, with APIs for document processing in multiple formats. | Provides access to linguistic corpora and text processing tools for tokenization, classification, parsing, and semantic analysis. Widely used in educational and research settings for computational linguistics work. |
| language.primary | - | Python |
| license.spdx | - | Apache-2.0 |
| market.availability | `{"hqCountry":"US","primaryMarkets":[],"availabilityScope":"global","availableCountries":[],"notAvailableCountries":[]}` | - |
| platform.support | `{"cli":true,"web":true}` | `{"cli":true,"mac":true,"linux":true,"windows":true}` |
| pricing | `{"type":"usage","plans":[{"free":false,"name":"Standard APIs (Pay-per-use)","summary":"$0.0001 per unit (100 characters)","features":["Entity recognition","Sentiment analysis","Syntax analysis","Key phrase extraction","Language detection","Event detection","Toxicity detection","Prompt safety classification","PII detection","Redaction"],"components":[{"per":{"qty":1,"unit":"unit"},"kind":"metered","note":"1 unit = 100 characters, 3-unit minimum per request","amount":0.0001,"currency":"USD"}],"description":"Entity recognition, sentiment analysis, syntax analysis, key phrase extraction, language detection, event detection, toxicity detection, prompt safety","contactSales":false,"includedLimits":{"free_tier":"50k units/month for 12 months"}},{"free":false,"name":"Custom Classification & Entities","summary":"$3/hour training + $0.50/month management + $0.0003/unit inference","features":["Custom model training","Custom entity extraction","Custom text classification","Model management"],"components":[{"kind":"one_time","note":"Model training, billed by the second","amount":3,"period":"hour","currency":"USD"},{"kind":"fixed","note":"Custom model management","amount":0.5,"period":"month","currency":"USD"},{"per":{"qty":1,"unit":"unit"},"kind":"metered","note":"Async inference at 100 characters per unit, 3-unit minimum","amount":0.0003,"currency":"USD"}],"description":"Train custom NLP models to categorize text and extract domain-specific entities","contactSales":false},{"free":false,"name":"Managed Endpoints (Synchronous)","summary":"$0.0005 per second per Inference Unit","features":["Real-time synchronous inference","Scalable throughput with multiple IUs"],"components":[{"per":{"qty":1,"unit":"second","quantity":"per Inference Unit"},"kind":"metered","note":"1 IU = 100 characters/sec throughput, minimum 60 seconds per billing period","amount":0.0005,"currency":"USD"}],"description":"Real-time inference endpoints with provisioned throughput","contactSales":false}],"summary":"From $0.0001 per unit (100 characters) for standard APIs. Free tier: 50K units per month for 12 months.","currency":"USD","freeTier":true,"sourceUrl":"https://aws.amazon.com/comprehend/pricing/?pg=ln&sec=hs","retrievedAt":"2026-08-19T16:04:06.586Z","startingPrice":{"amount":0.5,"period":"month","currency":"USD"},"billingPeriods":["month"]}` | `{"type":"open_source","summary":"Free and open source","freeTier":true,"sourceUrl":"https://www.nltk.org","retrievedAt":"2026-08-20T12:51:01.320Z"}` |
| pricing.free_tier | yes | yes |
| pricing.model | freemium | open_source |
| pricing.price_level | low | free |
| pricing.starting_price | `{"amount":0.5,"currency":"USD"}` | - |
| pricing.transparent | yes | yes |
| release.cadence_days | - | 2 |
| release.history | - | `[{"url":"https://github.com/nltk/nltk/releases/tag/v3.10.3-rc1","date":"2026-08-12T22:28:22Z","type":"stable","version":"v3.10.3-rc1"},{"url":"https://github.com/nltk/nltk/releases/tag/v3.10.3","date":"2026-08-13T06:56:10Z","type":"stable","version":"v3.10.3"},{"url":"https://github.com/nltk/nltk/releases/tag/v3.10.2-rc1","date":"2026-08-05T08:52:22Z","type":"stable","version":"v3.10.2-rc1"},{"url":"https://github.com/nltk/nltk/releases/tag/v3.10.2","date":"2026-08-05T10:02:22Z","type":"stable","version":"v3.10.2"},{"url":"https://github.com/nltk/nltk/releases/tag/v3.10.1-rc2","date":"2026-07-29T15:05:36Z","type":"stable","version":"v3.10.1-rc2"},{"url":"https://github.com/nltk/nltk/releases/tag/v3.10.1-rc1","date":"2026-07-27T08:37:09Z","type":"stable","version":"v3.10.1-rc1"},{"url":"https://github.com/nltk/nltk/releases/tag/v3.10.0","date":"2026-08-05T09:57:11Z","type":"stable","version":"v3.10.0"},{"url":"https://github.com/nltk/nltk/releases/tag/v3.10.0-rc1","date":"2026-06-11T21:07:13Z","type":"stable","version":"v3.10.0-rc1"}]` |
| security.disclosure_policy | yes | - |
| security.fedramp | yes | - |
| security.gdpr | yes | - |
| security.hipaa | yes | - |
| security.pci | yes | - |
| security.scorecard | - | 4.8 |
| security.vulnerabilities | - | `{"count":20,"source":"https://advisories.ecosyste.ms/api/v1/advisories?ecosystem=pypi&package_name=nltk&per_page=100","last_12m":15,"max_severity":"CRITICAL"}` |

## Capabilities (NLP Apis)

| Capability | Amazon Comprehend | NLTK |
|---|:--:|:--:|
| **Capabilities** |  |  |
| Custom model training | - | - |
| Domain specific models | - | - |
| Deployment model | - | - |
| Batch processing | - | - |
| Real time latency | - | - |
| Embeddings endpoint | - | - |
| Data residency EU | - | - |
| Open source | - | - |
| Pricing model | - | - |

*Source: Vioscale. Generated 2026-09-01T14:56:00.885Z. "-" = undocumented, not absent.*