PDF to Markdown Conversion (Docling)

Overview

Convert PDF documents to structured Markdown using the Docling library. Docling uses ML models to understand document layout, preserving headings, tables, lists, and reading order. For advanced pipeline configuration, OCR settings, and performance tuning, see reference.md.

Quick Start

from docling.document_converter import DocumentConverter

converter = DocumentConverter()
result = converter.convert("document.pdf")
markdown = result.document.export_to_markdown()

with open("document.md", "w", encoding="utf-8") as f:
    f.write(markdown)

Install: pip install docling

Docling Library

Basic Conversion

from docling.document_converter import DocumentConverter

converter = DocumentConverter()
result = converter.convert("paper.pdf")

# Export as Markdown
md = result.document.export_to_markdown()

# Page count
print(f"{len(result.document.pages)} pages")

Batch Conversion

from pathlib import Path
from docling.document_converter import DocumentConverter

converter = DocumentConverter()
output_dir = Path("markdown_outputs")
output_dir.mkdir(exist_ok=True)

for pdf in Path("papers/").glob("*.pdf"):
    result = converter.convert(str(pdf))
    md = result.document.export_to_markdown()
    (output_dir / f"{pdf.stem}.md").write_text(md, encoding="utf-8")
    print(f"Converted {pdf.name}")

Custom Output Path

from pathlib import Path
from docling.document_converter import DocumentConverter

def convert_pdf(pdf_path, output_path=None):
    pdf_path = Path(pdf_path)
    if output_path is None:
        output_path = pdf_path.with_suffix(".md")

    converter = DocumentConverter()
    result = converter.convert(str(pdf_path))
    Path(output_path).write_text(
        result.document.export_to_markdown(), encoding="utf-8"
    )
    return output_path

Pipeline Configuration

from docling.datamodel.pipeline_options import PdfPipelineOptions, TableFormerMode
from docling.document_converter import DocumentConverter, PdfFormatOption
from docling.datamodel.base_models import InputFormat

pipeline_options = PdfPipelineOptions()

# Use accurate table detection (slower but better for complex tables)
pipeline_options.table_structure_options.mode = TableFormerMode.ACCURATE

converter = DocumentConverter(
    format_options={
        InputFormat.PDF: PdfFormatOption(pipeline_options=pipeline_options)
    }
)
result = converter.convert("report.pdf")

Image Extraction

from pathlib import Path
from docling.datamodel.pipeline_options import PdfPipelineOptions
from docling.document_converter import DocumentConverter, PdfFormatOption
from docling.datamodel.base_models import InputFormat

pipeline_options = PdfPipelineOptions()
pipeline_options.generate_picture_images = True

converter = DocumentConverter(
    format_options={
        InputFormat.PDF: PdfFormatOption(pipeline_options=pipeline_options)
    }
)

result = converter.convert("paper.pdf")
image_dir = Path("images")
image_dir.mkdir(exist_ok=True)

for element, _level in result.document.iterate_items():
    if hasattr(element, 'image') and element.image is not None:
        img_path = image_dir / f"{element.self_ref}.png"
        element.image.pil_image.save(str(img_path))

OCR for Scanned Documents

from docling.datamodel.pipeline_options import PdfPipelineOptions
from docling.document_converter import DocumentConverter, PdfFormatOption
from docling.datamodel.base_models import InputFormat

pipeline_options = PdfPipelineOptions()
pipeline_options.do_ocr = True

converter = DocumentConverter(
    format_options={
        InputFormat.PDF: PdfFormatOption(pipeline_options=pipeline_options)
    }
)
result = converter.convert("scanned_document.pdf")
md = result.document.export_to_markdown()

Command-Line Usage

Basic Script

# Single file
python scripts/pdf_to_markdown.py report.pdf

# Single file with custom output
python scripts/pdf_to_markdown.py report.pdf output.md

# Batch convert a directory
python scripts/pdf_to_markdown.py ./papers/

# Batch with custom output directory
python scripts/pdf_to_markdown.py ./papers/ ./converted/

Advanced Script

# With image extraction
python scripts/pdf_to_markdown_advanced.py paper.pdf paper.md --with-images ./images

# With OCR for scanned documents
python scripts/pdf_to_markdown_advanced.py scanned.pdf output.md --ocr

# With accurate table detection
python scripts/pdf_to_markdown_advanced.py report.pdf report.md --accurate-tables

# Combine options
python scripts/pdf_to_markdown_advanced.py paper.pdf paper.md --ocr --accurate-tables --with-images ./img

Common Tasks

Academic Paper Conversion

Academic papers with sections, references, figures, and tables:

from docling.datamodel.pipeline_options import PdfPipelineOptions, TableFormerMode
from docling.document_converter import DocumentConverter, PdfFormatOption
from docling.datamodel.base_models import InputFormat

pipeline_options = PdfPipelineOptions()
pipeline_options.table_structure_options.mode = TableFormerMode.ACCURATE

converter = DocumentConverter(
    format_options={
        InputFormat.PDF: PdfFormatOption(pipeline_options=pipeline_options)
    }
)
result = converter.convert("paper.pdf")
md = result.document.export_to_markdown()

Lecture Slides

Slides often have sparse text with images — enable image extraction:

pipeline_options = PdfPipelineOptions()
pipeline_options.generate_picture_images = True

converter = DocumentConverter(
    format_options={
        InputFormat.PDF: PdfFormatOption(pipeline_options=pipeline_options)
    }
)
result = converter.convert("slides.pdf")

Table-Heavy Documents

For documents where table accuracy is critical:

pipeline_options = PdfPipelineOptions()
pipeline_options.table_structure_options.mode = TableFormerMode.ACCURATE

# Convert and check tables
converter = DocumentConverter(
    format_options={
        InputFormat.PDF: PdfFormatOption(pipeline_options=pipeline_options)
    }
)
result = converter.convert("data_report.pdf")
md = result.document.export_to_markdown()

Scanned PDFs

For scanned documents or image-based PDFs:

pipeline_options = PdfPipelineOptions()
pipeline_options.do_ocr = True

converter = DocumentConverter(
    format_options={
        InputFormat.PDF: PdfFormatOption(pipeline_options=pipeline_options)
    }
)
result = converter.convert("scanned.pdf")

Quick Reference

Error Handling

Next Steps

• For advanced pipeline configuration, OCR backends, export formats, chunking for RAG, and performance tuning, see reference.md
• For general PDF operations (merge, split, create, fill forms), see the pdf skill