Apache OpenNLP

aid: apache-opennlp
name: Apache OpenNLP
description: Apache OpenNLP is a machine learning based toolkit for the processing of natural language text. It supports common
  NLP tasks such as tokenization, sentence segmentation, part-of-speech tagging, named entity extraction, chunking, parsing,
  and coreference resolution.
type: Index
position: Consumer
access: 3rd-Party
image: https://kinlane-productions2.s3.amazonaws.com/apis-json/apis-json-logo.jpg
tags:
- Machine Learning
- Natural Language Processing
- NLP
- Text Processing
- Apache
- Open Source
- Java
created: '2026-03-16'
modified: '2026-05-19'
url: https://raw.githubusercontent.com/api-evangelist/apache-opennlp/refs/heads/main/apis.yml
specificationVersion: '0.19'
apis:
- aid: apache-opennlp:apache-opennlp
  name: Apache OpenNLP
  description: OpenNLP provides a Java API for NLP tasks including tokenization, sentence detection, POS tagging, named entity
    recognition, chunking, parsing, and language detection, with support for training custom models.
  humanURL: https://opennlp.apache.org/docs/
  tags:
  - Java
  - NLP
  - Text Processing
  - Apache
  - Open Source
  - Machine Learning
  properties:
  - type: Documentation
    url: https://opennlp.apache.org/docs/
  - type: OpenAPI
    url: openapi/apache-opennlp-tools.yaml
  - type: NaftikoCapability
    url: capabilities/tools-chunking.yaml
  - type: NaftikoCapability
    url: capabilities/tools-document-categorization.yaml
  - type: NaftikoCapability
    url: capabilities/tools-language-detection.yaml
  - type: NaftikoCapability
    url: capabilities/tools-lemmatization.yaml
  - type: NaftikoCapability
    url: capabilities/tools-models.yaml
  - type: NaftikoCapability
    url: capabilities/tools-named-entity-recognition.yaml
  - type: NaftikoCapability
    url: capabilities/tools-pos-tagging.yaml
  - type: NaftikoCapability
    url: capabilities/tools-parsing.yaml
  - type: NaftikoCapability
    url: capabilities/tools-sentence-detection.yaml
  - type: NaftikoCapability
    url: capabilities/tools-tokenization.yaml
maintainers:
- FN: Kin Lane
  email: [email protected]
common:
- type: GitHubOrganization
  url: https://github.com/apache/opennlp
- type: Documentation
  url: https://opennlp.apache.org/
- type: GettingStarted
  url: https://opennlp.apache.org/docs/
- type: SpectralRules
  url: rules/apache-opennlp-spectral-rules.yml
- type: Vocabulary
  url: vocabulary/apache-opennlp-vocabulary.yaml
- type: JSONLD
  url: json-ld/apache-opennlp-context.jsonld
- type: Features
  data:
  - name: Language Detection
    description: Detects document language using ISO-639-3 classification
  - name: Sentence Detection
    description: Splits text into individual sentences with character offsets
  - name: Tokenization
    description: Segments text into words and punctuation with position tracking
  - name: Named Entity Recognition
    description: Detects persons, locations, organizations, and other named entities
  - name: POS Tagging
    description: Assigns Penn Treebank POS tags to each token
  - name: Lemmatization
    description: Reduces tokens to their dictionary base forms
  - name: Chunking
    description: Identifies noun phrases, verb phrases, and other syntactic chunks
  - name: Parsing
    description: Builds full syntactic parse trees using constituency parsing
  - name: Document Categorization
    description: Classifies documents into predefined categories
  - name: Custom Model Training
    description: Train custom models with Maxent, Perceptron, or Naive Bayes algorithms
- type: UseCases
  data:
  - name: Information Extraction
    description: Extract structured data from unstructured text documents
  - name: Text Classification
    description: Automatically categorize documents by topic or sentiment
  - name: Search Enhancement
    description: Improve search relevance with NLP-based query processing
  - name: Content Analysis
    description: Analyze large text corpora for entities, topics, and patterns
  - name: Chatbot Development
    description: Build conversational AI with NLP intent and entity extraction
- type: Integrations
  data:
  - name: Apache Solr
    description: Integrate OpenNLP with Apache Solr for NLP-enhanced search
  - name: Apache Lucene
    description: Use OpenNLP analyzers in Lucene text processing pipelines
  - name: Apache Flink
    description: Real-time NLP processing with Apache Flink data streams
  - name: UIMA
    description: Apache UIMA framework integration for unstructured information analysis
  - name: Maven/Gradle
    description: Available on Maven Central for Java build system integration