DocSlicer

DocSlicer

Lightning-fast (31 pages/sec), deterministic document parser and chunker for business documents. No LLM calls or heavy ML models.

DocSlicer turns PDFs, Word documents, HTML pages, and PowerPoint files into clean chunks, structured blocks, tables, charts, markdown and a navigable heading hierarchy.

Top score on BizDocBench (0.88 overall vs 0.70 for the next-best tool). 0.80 table accuracy, 0.98 content faithfulness, 0.85 heading recognition and hierarchy preservation, and 0.76 RAG retrieval performance.

Two ways to use it:

• As a Python library — classic RAG. The layout-aware chunker gives you clean, non-overlapping chunks, each carrying its full heading breadcrumb, ready to embed. Jump to the API ↓
• As an MCP server — vectorless RAG. For when you want an answer out of a document right now. Claude, Cursor, or VS Code pulls the outline, picks the section it needs, and reads only that — no embedding, and no 200-page document in the context window. Jump to setup ↓

Quick start

import docslicer

def main(): result = docslicer.parse_document("annual_report.pdf")

Inspect the outline first

result.hierarchy.to_outline()

- PART I — FINANCIAL INFORMATION

- Item 1. Financial Statements

- Notes to Condensed Consolidated Financial Statements

- Note 4 – Financial Instruments

- Derivative Instruments and Hedging

- Foreign Exchange Rate Risk

- Interest Rate Risk

- Accounts Receivable

- Trade Receivables

- Item 2. Management's Discussion and Analysis

- Liquidity and Capital Resources

- PART II — OTHER INFORMATION

...

Pull only the chunks you need

risk_section = result.find_heading("Risk Factors")[0] chunks = result.chunks_under(risk_section)

Tables come back structured, not as flat text

for table in result.tables_under(risk_section): print(table.markdown)

if name == "main": main()

Features

• No LLM, VLM, or ML models — fully deterministic; no model weights to download, no GPU required, no cold-start delay
• Lightweight — ~630 KB wheel with no heavy ML dependencies
• Agentic-friendly — reduces token spend on long documents: have the agent inspect the outline first, then pull only the relevant chunks into context instead of feeding a 500-page document verbatim; well-suited for legal texts, technical SOPs, financial filings, and compliance documents
• Deep hierarchy extraction — works for both numbered (1., 1.2., 1.2.3) and free-form headings; uses font size, bold weight, and document structure — not inference; handles re-entry after exhibit breaks and repeated navigation headings across pages
• Structure-aware chunking — splits at heading and paragraph boundaries, preserving semantic coherence
• Zero character overlap — chunks are non-overlapping by default; no duplicated tokens in your context window
• Unified result object — chunks, blocks, tables, charts, metadata, and hierarchy in one place
• Structured tables — tables come back as cells, not flat text; export as Markdown, JSONL, or melted format
• Multiple export formats — CSV, Markdown, JSONL, Parquet, JSON, plain text, and DataFrames
• Reading order preserved — including multi-column PDF layouts
• Supports `pdf`, `docx`, `pptx`, and `html` — including JS-rendered pages via Playwright
• Robust URL fetching — always renders pages in a real browser, handling cookie banners and bot protection out of the box; also preserves styling signals like boldness that raw HTML omits, producing sharper heading detection and chunk quality
• OCR fallback — auto-detects scanned pages and falls back to Tesseract when the extra is installed

Benchmarks

Measured with BizDocBench — an open benchmark for multi-format business document parsing. All scores are 0–1 (higher is better); pages_per_sec_aggregate is throughput across the full corpus.

Install

pip install docslicer

The core install is dependency-light. Optional features are available as extras:

pip install 'docslicer[html]'    # HTML / URL parsing via Playwright

playwright install chromium # one-time browser install (Chromium only)

pip install 'docslicer[ocr]' # scanned PDF support via Tesseract + OpenCV

The tesserocr wheel bundles libtesseract but NOT the language models,

so install the Tesseract engine to provide them (docslicer auto-detects the path):

Linux: apt install tesseract-ocr

macOS: brew install tesseract

pip install 'docslicer[mcp]' # MCP server for LLM clients (Claude, Cursor, …) pip install 'docslicer[llm]' # exact token counts via tiktoken (exact_tokens=True) pip install 'docslicer[crypto]' # password-protected Office files (msoffcrypto-tool) pip install 'docslicer[parquet]' # Parquet export support

Extras can be combined: pip install 'docslicer[html,ocr,llm]'.

Requires Python 3.10+

What you get back (ParseResult)

parse_document returns a ParseResult:

result.chunks      # list[Chunk]   — heading-aware text chunks, ready for embedding

result.blocks # list[Block] — paragraph/heading/table blocks before chunking result.tables # list[Table] — structured tables with cells, spans, and markdown result.charts # list[Chart] — charts as extracted data points (docx/pptx) result.metadata # DocumentMetadata — title, author, language, page count, OCR flag result.hierarchy # HierarchyTree — navigable tree of all headings

Each Chunk carries:

chunk.text          # str   — chunk text

chunk.path # list — full heading breadcrumb from root to nearest heading chunk.heading # str — nearest heading above this chunk chunk.section # str — body | toc | exhibit | header | footer | coverpage | … chunk.page_number # int — 1-based physical page chunk.page_label # str — "A-6", "iv", "F-3" — as printed on the page chunk.table_ids # list — IDs of tables referenced in this chunk chunk.chart_ids # list — IDs of charts referenced in this chunk (docx/pptx) chunk.link_url # list — URLs found in this chunk chunk.bbox # BBox — bounding box (PDF only)

Every chunk carries its full heading breadcrumb, no matter how deeply nested. For example, a paragraph six levels deep in a financial filing:

chunk.path == [

"# PART I — FINANCIAL INFORMATION", "## Item 1. Financial Statements", "### Notes to Condensed Consolidated Financial Statements (Unaudited)", "#### Note 4 – Financial Instruments", "##### Accounts Receivable", "###### Trade Receivables", ]

This lets downstream code filter or group chunks by any level of the hierarchy without re-parsing the document.

Supported formats

Not supported: .doc, .ppt (legacy Office formats), .xlsx.

Parsing

parse_document auto-detects the format from the file extension or magic bytes. Pass a file path, URL, raw bytes, or a file-like object:

result = docslicer.parse_document("contract.docx")

result = docslicer.parse_document("report.pdf") result = docslicer.parse_document("https://www.sec.gov/Archives/edgar/data/.../10-K.htm") result = docslicer.parse_document(file_bytes)

Parsing & content options

parse_document (and the format-specific functions) accept options that control what gets parsed and how, before it's chunked. Format-specific toggles are accepted everywhere for a uniform API but only take effect for the relevant format.

result = docslicer.parse_document(

"contract.docx", password="admin123", # decrypt password-protected files; .docx and .pptx needs [crypto] extra max_workers=4, # process-pool width for PDF extraction/OCR (default: auto by CPU cores) include_headers_footers=True, # docx: include header/footer content (default False) include_footnotes=True, # docx: include footnotes (default True) include_comments=True, # docx: include review comments (default False) include_speaker_notes=True, # pptx: include slide speaker notes (default True) use_browser=True, # html/URL: render in a real browser (default True) )

Chunking options

result = docslicer.parse_document(

"report.pdf", max_chunk_size=2000, # hard cap, default 3200 optimal_chunk_size=800, # target size, default 1500 min_chunk_size=400, # soft floor, default 700 chunking=False, # skip chunking, return blocks only (faster) merge_small_chunks=True, # merge chunks below min_chunk_size (default True) table_representation="jsonl", # "markdown" (default) | "jsonl" | "melted" exact_tokens=True, # exact tiktoken (cl100k_base) counts; needs [llm] extra, else char/4 estimate extra_fields=["is_bold", "font_size", "font_name"], # surface internal pipeline columns on each chunk/block via .extra )

How merge_small_chunks works

Because DocSlicer is structure-aware, it initially produces one chunk per heading or paragraph boundary. For documents with many short sections this can yield a lot of small chunks. With merge_small_chunks=True (the default), sibling sections under the same parent heading are merged together until they reach min_chunk_size — but never a