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> **Comprehensive document chunking and splitting for optimal processing with 15+ methods including KG-aware, semantic, and structural chunking.**

May 2, 2026
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Split

Comprehensive document chunking and splitting for optimal processing with 15+ methods including KG-aware, semantic, and structural chunking.


🎯 Overview

<div class="grid cards" markdown>
  • :material-content-cut:{ .lg .middle } Multiple Methods


    15+ chunking methods: recursive, semantic, entity-aware, relation-aware, and more

  • :material-graph:{ .lg .middle } KG-Aware Chunking


    Preserve entities, relationships, and graph structure for GraphRAG workflows

  • :material-brain:{ .lg .middle } Semantic Chunking


    Intelligent boundary detection using embeddings and NLP

  • :material-file-tree:{ .lg .middle } Structural Chunking


    Respect document structure: headings, paragraphs, lists, tables

  • :material-check-circle:{ .lg .middle } Quality Validation


    Chunk quality assessment and validation

  • :material-source-branch:{ .lg .middle } Provenance Tracking


    Track chunk origins for data lineage

</div>

!!! tip "Choosing the Right Method" - Standard Documents: Use recursive or sentence for general text - GraphRAG: Use entity_aware or relation_aware to preserve knowledge - Semantic Coherence: Use semantic_transformer for topic-based chunks - Structured Docs: Use structural for documents with headings/sections - Large Documents: Use hierarchical for multi-level chunking


⚙️ Algorithms Used

Standard Splitting Algorithms

Purpose: Split documents into chunks using various strategies.

How it works:

  • Recursive Splitting: Separator hierarchy (`\n\n`, `\n`, ` `, ``) with greedy splitting
  • Token Counting: BPE tokenization using tiktoken or transformers
  • Sentence Segmentation: NLTK punkt, spaCy sentencizer, or regex-based
  • Paragraph Detection: Double newline detection with whitespace normalization
  • Character Splitting: Fixed-size character chunks with overlap
  • Word Splitting: Whitespace tokenization with word boundary preservation

Semantic Chunking Algorithms

Purpose: Intelligent boundary detection using embeddings and NLP.

How it works:

  • Semantic Boundary Detection:
    • Sentence transformer embeddings (384-1024 dim)
    • Cosine similarity between consecutive sentences
    • Threshold-based boundary detection (default: `0.7`)
  • LLM-based Splitting:
    • Prompt engineering for optimal split point detection
    • Context window management
    • Coherence scoring

KG/Ontology Chunking Algorithms

Purpose: Preserve entities, relationships, and graph structure for GraphRAG workflows.

How it works:

  • Entity Boundary Detection:
    • NER-based entity extraction (spaCy, LLM)
    • Entity span tracking
    • Boundary preservation (no entity splitting)
  • Triplet Preservation:
    • Graph-based triplet integrity checking
    • Subject-predicate-object span tracking
    • Relationship boundary preservation
  • Graph Centrality Analysis:
    • Degree centrality: `C_D(v) = deg(v) / (n-1)`
    • Betweenness centrality: `C_B(v) = Σ(σ_st(v) / σ_st)`
    • Closeness centrality: `C_C(v) = (n-1) / Σd(v,u)`
    • Eigenvector centrality: Power iteration method
  • Community Detection:
    • Louvain algorithm: Modularity optimization O(n log n)
    • Leiden algorithm: Improved Louvain with refinement
    • Modularity calculation: Q = (1/2m) Σ[A_ij - k_i*k_j/2m]δ(c_i,c_j)

Structural Chunking Algorithms

  • Heading Detection: Markdown/HTML heading parsing
  • List Detection: Ordered/unordered list identification
  • Table Detection: Table boundary identification
  • Section Hierarchy: Tree-based section structure

Validation Algorithms

  • Chunk Size Validation: Min/max size checking
  • Overlap Validation: Overlap percentage calculation
  • Completeness Check: Coverage verification
  • Quality Scoring: Multi-factor quality assessment

Main Classes

TextSplitter

Unified text splitter with method parameter for all chunking strategies.

Methods:

MethodDescriptionAlgorithm
split(text)Split text using configured methodMethod-specific algorithm
split_documents(documents)Batch split documentsParallel processing
split_with_metadata(text, metadata)Split with metadata preservationMetadata propagation
validate_chunks(chunks)Validate chunk qualityQuality assessment

Supported Methods:

CategoryMethods
Standardrecursive, token, sentence, paragraph, character, word
Semanticsemantic_transformer, llm, huggingface, nltk
KG/Ontologyentity_aware, relation_aware, graph_based, ontology_aware
Advancedhierarchical, community_detection, centrality_based, subgraph, topic_based

Configuration Options:

TextSplitter(
    method="recursive",           # Chunking method
    chunk_size=1000,             # Target chunk size (characters/tokens)
    chunk_overlap=200,           # Overlap between chunks
    length_function=len,         # Function to measure chunk size
    separators=["\n\n", "\n", " ", ""],  # For recursive method
    keep_separator=True,         # Keep separators in chunks
    add_start_index=True,        # Add start index to metadata
    strip_whitespace=True,       # Strip whitespace from chunks
    
    # Semantic chunking options
    embedding_model="all-MiniLM-L6-v2",  # For semantic_transformer
    similarity_threshold=0.7,    # Semantic boundary threshold
    
    # Entity-aware options
    ner_method="ml",             # NER method (ml/spacy, llm, pattern)
    preserve_entities=True,      # Don't split entities
    
    # LLM options
    llm_provider="openai",       # LLM provider
    llm_model="gpt-4",          # LLM model
    
    # Graph-based options
    centrality_method="degree",  # Centrality measure
    community_algorithm="louvain",  # Community detection algorithm
)

Example:

from semantica.split import TextSplitter

# Standard recursive splitting
splitter = TextSplitter(
    method="recursive",
    chunk_size=1000,
    chunk_overlap=200
)
chunks = splitter.split(long_text)

for i, chunk in enumerate(chunks):
    print(f"Chunk {i}: {len(chunk.text)} chars")
    print(f"Metadata: {chunk.metadata}")

# Entity-aware for GraphRAG
splitter = TextSplitter(
    method="entity_aware",
    ner_method="ml",
    chunk_size=1000,
    preserve_entities=True
)
chunks = splitter.split(text)

# Semantic chunking
splitter = TextSplitter(
    method="semantic_transformer",
    embedding_model="all-MiniLM-L6-v2",
    similarity_threshold=0.7
)
chunks = splitter.split(text)

# Hierarchical chunking
splitter = TextSplitter(
    method="hierarchical",
    chunk_sizes=[2000, 1000, 500],  # Multi-level
    chunk_overlaps=[400, 200, 100]
)
chunks = splitter.split(text)

SemanticChunker

Semantic-based chunking using embeddings and similarity.

Methods:

MethodDescriptionAlgorithm
chunk(text)Chunk by semantic boundariesEmbedding similarity
find_boundaries(sentences)Find semantic boundariesThreshold-based detection
calculate_similarity(sent1, sent2)Calculate similarityCosine similarity

Example:

from semantica.split import SemanticChunker

chunker = SemanticChunker(
    embedding_model="all-MiniLM-L6-v2",
    similarity_threshold=0.7,
    min_chunk_size=100,
    max_chunk_size=2000
)

chunks = chunker.chunk(long_text)

for chunk in chunks:
    print(f"Chunk: {chunk.text[:100]}...")
    print(f"Coherence score: {chunk.metadata.get('coherence_score')}")

EntityAwareChunker

Preserve entity boundaries during chunking for GraphRAG.

Methods:

MethodDescriptionAlgorithm
chunk(text, entities)Chunk preserving entitiesEntity boundary detection

Example:

from semantica.split import EntityAwareChunker
from semantica.semantic_extract import NERExtractor

# Extract entities first
ner = NERExtractor(method="ml")
entities = ner.extract(text)

# Chunk preserving entities
chunker = EntityAwareChunker(
    chunk_size=1000,
    chunk_overlap=200,
    ner_method="ml"
)

chunks = chunker.chunk(text, entities=entities)

for chunk in chunks:
    print(f"Entities in chunk: {chunk.metadata.get('entities')}")

RelationAwareChunker

Preserve relationship triplets during chunking.

Methods:

MethodDescriptionAlgorithm
chunk(text, relationships)Chunk preserving tripletsTriplet span tracking
extract_relationships(text)Extract relationshipsRelation extraction
validate_triplet_integrity(chunk, relationships)Validate tripletsIntegrity checking

Example:

from semantica.split import RelationAwareChunker
from semantica.semantic_extract import RelationExtractor

# Extract relationships
rel_extractor = RelationExtractor()
relationships = rel_extractor.extract(text)

# Chunk preserving relationships
chunker = RelationAwareChunker(
    chunk_size=1000,
    preserve_triplets=True
)

chunks = chunker.chunk(text, relationships=relationships)

for chunk in chunks:
    print(f"Relationships: {chunk.metadata.get('relationships')}")

GraphBasedChunker

Chunk based on graph structure and centrality.

Methods:

MethodDescriptionAlgorithm
chunk(text, graph)Chunk by graph structureCentrality-based
calculate_centrality(graph)Calculate node centralityDegree/betweenness/closeness
detect_communities(graph)Detect communitiesLouvain/Leiden algorithm

Example:

from semantica.split import GraphBasedChunker
from semantica.kg import GraphBuilder

# Build graph
builder = GraphBuilder()
kg = builder.build(entities, relationships)

# Chunk by graph structure
chunker = GraphBasedChunker(
    centrality_method="betweenness",
    community_algorithm="louvain"
)

chunks = chunker.chunk(text, graph=kg)

for chunk in chunks:
    print(f"Community: {chunk.metadata.get('community_id')}")
    print(f"Centrality: {chunk.metadata.get('avg_centrality')}")

StructuralChunker

Structure-aware chunking respecting document hierarchy.

Methods:

MethodDescriptionAlgorithm
chunk(text)Chunk by structureHeading/section detection
_extract_structure(text)Extract structural elementsMarkdown/HTML parsing

Example:

from semantica.split import StructuralChunker

chunker = StructuralChunker(
    respect_headers=True,
    respect_sections=True,
    max_chunk_size=2000
)

chunks = chunker.chunk(markdown_text)

for chunk in chunks:
    print(f"Structure preserved: {chunk.metadata.get('structure_preserved')}")
    print(f"Elements: {chunk.metadata.get('element_types')}")

HierarchicalChunker

Multi-level hierarchical chunking.

Methods:

MethodDescriptionAlgorithm
chunk(text)Multi-level chunkingRecursive hierarchical split

Example:

from semantica.split import HierarchicalChunker

chunker = HierarchicalChunker(
    chunk_sizes=[2000, 1000, 500],
    chunk_overlaps=[400, 200, 100],
    create_parent_chunks=True
)

chunks = chunker.chunk(long_text)

for chunk in chunks:
    print(f"Level: {chunk.metadata.get('level')}")
    print(f"Parent: {chunk.metadata.get('parent_id')}")
    print(f"Children: {chunk.metadata.get('child_ids')}")

OntologyAwareChunker

Chunk based on ontology concepts and relationships.

Methods:

MethodDescriptionAlgorithm
chunk(text, ontology)Chunk by ontology conceptsConcept boundary detection
extract_concepts(text)Extract ontology conceptsConcept extraction
find_concept_boundaries(text, concepts)Find concept boundariesConcept span checking

Parameters:

ParameterTypeDefaultDescription
chunk_sizeint1000Target chunk size
chunk_overlapint200Overlap between chunks
ontology_pathstrNonePath to ontology file (.owl, .rdf)
preserve_conceptsboolTrueDon't split ontology concepts
concept_extraction_methodstr"llm"Method for concept extraction

Example:

from semantica.split import OntologyAwareChunker

chunker = OntologyAwareChunker(
    chunk_size=1000,
    chunk_overlap=200,
    ontology_path="domain_ontology.owl",
    preserve_concepts=True,
    concept_extraction_method="llm"
)

chunks = chunker.chunk(text)

for chunk in chunks:
    concepts = chunk.metadata.get('concepts', [])
    print(f"Concepts in chunk: {[c['label'] for c in concepts]}")
    print(f"Concept types: {[c['type'] for c in concepts]}")

SlidingWindowChunker

Fixed-size sliding window chunking with configurable step size.

Methods:

MethodDescriptionAlgorithm
chunk(text)Sliding window chunkingFixed-size window with step
chunk_with_overlap(text)Chunk with specific overlapWindow position calculation

Parameters:

ParameterTypeDefaultDescription
chunk_sizeint1000Size of sliding window
overlapint0Overlap size
strideintchunk_size - overlapStep size

Example:

from semantica.split import SlidingWindowChunker

# Basic sliding window
chunker = SlidingWindowChunker(
    chunk_size=1000,
    overlap=200
)

chunks = chunker.chunk(long_text)

for i, chunk in enumerate(chunks):
    print(f"Window {i}: chars {chunk.start_index}-{chunk.end_index}")
    print(f"Has overlap: {chunk.metadata.get('has_overlap')}")

# Boundary-preserving sliding window
chunks = chunker.chunk(text, preserve_boundaries=True)

TableChunker

Table-specific chunking preserving table structure.

Methods:

MethodDescriptionAlgorithm
chunk_table(table_data)Chunk tablesRow/Column-based splitting
chunk_to_text_chunks(table_data)Convert table chunks to textTable to text conversion
extract_table_schema(table_data)Extract schemaType inference and schema extraction

Parameters:

ParameterTypeDefaultDescription
max_rowsint100Maximum rows per table chunk
preserve_headersboolTrueKeep headers in each chunk
chunk_by_columnsboolFalseChunk by columns instead of rows

Example:

from semantica.split import TableChunker

chunker = TableChunker(
    max_rows=50,
    preserve_headers=True,
    chunk_by_columns=False
)

table_data = {
    "headers": ["Col1", "Col2", "Col3"],
    "rows": [["Val1", "Val2", "Val3"], ...]
}

# Get structured table chunks
table_chunks = chunker.chunk_table(table_data)

# Get text chunks for RAG
text_chunks = chunker.chunk_to_text_chunks(table_data)

for chunk in text_chunks:
    print(f"Table chunk {chunk.metadata.get('chunk_index')}")
    print(f"Rows: {chunk.metadata.get('row_count')}")

ChunkValidator

Validate chunk quality and completeness.

Methods:

MethodDescriptionAlgorithm
validate(chunks)Validate chunksMulti-factor validation
check_size(chunk)Check size constraintsMin/max checking
check_overlap(chunks)Check overlapOverlap calculation
check_completeness(chunks, original)Check coverageCoverage verification
calculate_quality_score(chunk)Quality scoreMulti-factor scoring

Example:

from semantica.split import ChunkValidator

validator = ChunkValidator(
    min_chunk_size=100,
    max_chunk_size=2000,
    min_overlap=50,
    max_overlap=500
)

validation_result = validator.validate(chunks)

print(f"Valid: {validation_result['valid']}")
print(f"Issues: {validation_result['issues']}")
print(f"Quality score: {validation_result['quality_score']}")

ProvenanceTracker

Track chunk provenance for data lineage.

Methods:

MethodDescriptionAlgorithm
track(chunk, source)Track chunk originProvenance recording
get_lineage(chunk_id)Get chunk lineageLineage retrieval
visualize_lineage(chunk_id)Visualize lineageGraph visualization

Example:

from semantica.split import ProvenanceTracker

tracker = ProvenanceTracker()

for chunk in chunks:
    tracker.track(
        chunk=chunk,
        source={
            "document_id": "doc123",
            "file_path": "data/document.pdf",
            "page": 5,
            "timestamp": "2024-01-01T00:00:00Z"
        }
    )

# Get lineage
lineage = tracker.get_lineage(chunk.id)
print(f"Source: {lineage['source']}")
print(f"Transformations: {lineage['transformations']}")

Convenience Functions

Quick access to splitting operations:

from semantica.split import (
    split_recursive,
    split_by_tokens,
    split_by_sentences,
    split_by_paragraphs,
    split_entity_aware,
    split_relation_aware,
    split_semantic_transformer,
    list_available_methods
)

# List available methods
methods = list_available_methods()
print(f"Available methods: {methods}")

# Quick splitting
chunks = split_recursive(text, chunk_size=1000, chunk_overlap=200)
chunks = split_by_sentences(text, sentences_per_chunk=5)
chunks = split_entity_aware(text, ner_method="ml")

Configuration

Environment Variables

# Default settings
export SPLIT_DEFAULT_METHOD=recursive
export SPLIT_DEFAULT_CHUNK_SIZE=1000
export SPLIT_DEFAULT_CHUNK_OVERLAP=200

# Semantic chunking
export SPLIT_EMBEDDING_MODEL=all-MiniLM-L6-v2
export SPLIT_SIMILARITY_THRESHOLD=0.7

# Entity-aware
export SPLIT_NER_METHOD=ml  # or spacy
export SPLIT_PRESERVE_ENTITIES=true

# LLM-based
export SPLIT_LLM_PROVIDER=openai
export SPLIT_LLM_MODEL=gpt-4

YAML Configuration

# config.yaml - Split Module Configuration

split:
  default_method: recursive
  chunk_size: 1000
  chunk_overlap: 200
  
  recursive:
    separators: ["\n\n", "\n", " ", ""]
    keep_separator: true
    
  semantic:
    embedding_model: all-MiniLM-L6-v2
    similarity_threshold: 0.7
    min_chunk_size: 100
    max_chunk_size: 2000
    
  entity_aware:
    ner_method: ml  # or spacy
    preserve_entities: true
    min_entity_gap: 50
    
  relation_aware:
    preserve_triplets: true
    relation_extraction_method: llm
    
  graph_based:
    centrality_method: betweenness
    community_algorithm: louvain
    min_community_size: 3
    
  hierarchical:
    levels: 3
    chunk_sizes: [2000, 1000, 500]
    chunk_overlaps: [400, 200, 100]
    
  validation:
    enabled: true
    min_chunk_size: 100
    max_chunk_size: 2000
    check_overlap: true
    check_completeness: true

Method Comparison

MethodBest ForProsCons
recursiveGeneral textFast, simpleMay split mid-sentence
sentenceCoherent chunksRespects sentencesVariable size
semantic_transformerTopic coherenceSemantic boundariesSlower, needs embeddings
entity_awareGraphRAGPreserves entitiesRequires NER
relation_awareKG extractionPreserves tripletsRequires relation extraction
graph_basedGraph analysisGraph-awareRequires graph construction
hierarchicalLarge documentsMulti-levelMore complex
structuralFormatted docsRespects structureNeeds structure

Integration Examples

Complete GraphRAG Pipeline

from semantica.split import TextSplitter
from semantica.semantic_extract import NERExtractor, RelationExtractor
from semantica.kg import GraphBuilder
from semantica.embeddings import EmbeddingGenerator
from semantica.vector_store import VectorStore

# Parse document
text = "Apple Inc. was founded by Steve Jobs in 1976..."

# Entity-aware chunking
splitter = TextSplitter(
    method="entity_aware",
    ner_method="llm",
    chunk_size=1000
)
chunks = splitter.split(text)

# Extract from each chunk
ner = NERExtractor(method="llm")
rel_extractor = RelationExtractor()

all_entities = []
all_relationships = []

for chunk in chunks:
    entities = ner.extract(chunk.text)
    relationships = rel_extractor.extract(chunk.text, entities)
    
    all_entities.extend(entities)
    all_relationships.extend(relationships)

# Build knowledge graph
builder = GraphBuilder()
kg = builder.build(all_entities, all_relationships)

# Generate embeddings
embedder = EmbeddingGenerator()
embeddings = embedder.generate([chunk.text for chunk in chunks])

# Store in vector store
vector_store = VectorStore()
vector_store.store(embeddings, chunks)

Multi-Level Hierarchical Chunking

from semantica.split import HierarchicalChunker

chunker = HierarchicalChunker(
    chunk_sizes=[4000, 2000, 1000],
    chunk_overlaps=[800, 400, 200],
    create_parent_chunks=True
)

chunks = chunker.chunk(very_long_document)

# Access hierarchy
for chunk in chunks:
    level = chunk.metadata['level']
    parent_id = chunk.metadata.get('parent_id')
    child_ids = chunk.metadata.get('child_ids', [])
    
    print(f"Level {level}: {len(chunk.text)} chars")
    if parent_id:
        print(f"  Parent: {parent_id}")
    if child_ids:
        print(f"  Children: {len(child_ids)}")

Best Practices

1. Choose Appropriate Chunk Size

# For semantic search (embeddings)
splitter = TextSplitter(method="recursive", chunk_size=512)

# For LLM context (GPT-4)
splitter = TextSplitter(method="recursive", chunk_size=4000)

# For entity extraction
splitter = TextSplitter(method="entity_aware", chunk_size=1000)

2. Use Overlap for Context

# 20% overlap recommended
splitter = TextSplitter(
    chunk_size=1000,
    chunk_overlap=200  # 20%
)

3. Validate Chunks

from semantica.split import ChunkValidator

validator = ChunkValidator()
validation = validator.validate(chunks)

if not validation['valid']:
    print(f"Issues: {validation['issues']}")

4. Track Provenance

from semantica.split import ProvenanceTracker

tracker = ProvenanceTracker()
for chunk in chunks:
    tracker.track(chunk, source={"doc_id": "123"})

Troubleshooting

Issue: Chunks too small/large

# Solution: Adjust chunk size and method
splitter = TextSplitter(
    method="recursive",
    chunk_size=1500,  # Increase
    chunk_overlap=300
)

# Or use validation
validator = ChunkValidator(min_chunk_size=500, max_chunk_size=2000)

Issue: Entities split across chunks

# Solution: Use entity-aware chunking
splitter = TextSplitter(
    method="entity_aware",
    ner_method="llm",
    preserve_entities=True
)

Issue: Slow semantic chunking

# Solution: Use faster embedding model or batch processing
splitter = TextSplitter(
    method="semantic_transformer",
    embedding_model="all-MiniLM-L6-v2",  # Faster model
    batch_size=32  # Batch embeddings
)

Performance Tips

Memory Optimization

# Process in batches
def chunk_large_corpus(documents, batch_size=100):
    splitter = TextSplitter(method="recursive")
    
    for i in range(0, len(documents), batch_size):
        batch = documents[i:i + batch_size]
        chunks = splitter.split_documents(batch)
        yield from chunks

Speed Optimization

# Use faster methods for large documents
splitter = TextSplitter(
    method="recursive",  # Fastest
    chunk_size=1000
)

# Avoid LLM-based for large corpora
# Use semantic_transformer instead of llm

See Also

Cookbook

Interactive tutorials to learn text chunking and splitting:

  • Chunking and Splitting: Split documents for RAG and processing
    • Topics: Recursive character splitting, semantic splitting, token-based splitting, chunking strategies
    • Difficulty: Beginner
    • Use Cases: Preparing text for RAG, document chunking

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