libvisio-ng

A Python library for parsing and converting Microsoft Visio files to SVG.

Native support for both .vsdx (XML) and .vsd (binary) formats — no external C++ dependencies required.

Features

• Native .vsdx parsing — zero external dependencies for XML-based Visio formats
• Native .vsd parsing — binary OLE2 format support via olefile (no libvisio/C++ needed)
• Theme support — resolves Visio themes, gradients, and shadows
• Text extraction — extract all text content from diagrams
• Page metadata — enumerate pages with dimensions and names
• SVG output — high-fidelity SVG conversion with geometry, text, and styling
• CLI tool — visio2svg command for quick conversions
• PNG/PDF export — optional CairoSVG-based rasterization

Installation

pip install libvisio-ng

For PNG/PDF export support:

pip install libvisio-ng[png]

Quick Start

from libvisio_ng import convert, get_page_info, extract_text

# Convert all pages to SVG (works with both .vsdx and .vsd)
svg_files = convert("diagram.vsdx", output_dir="output/")
svg_files = convert("legacy.vsd", output_dir="output/")

# Get page information
for page in get_page_info("diagram.vsdx"):
    print(f"{page['name']}: {page['width']}x{page['height']}")

# Extract text
text = extract_text("diagram.vsdx")

Working with .vsd binary files directly

from libvisio_ng._vsd_parser import parse_vsd_file

doc = parse_vsd_file("legacy.vsd")
for page in doc.pages:
    print(f"Page: {page.name} ({page.width}x{page.height} inches)")
    for shape in page.shapes:
        if shape.text:
            print(f"  Shape {shape.shape_id}: {shape.text}")
        print(f"    Position: ({shape.xform.pin_x}, {shape.xform.pin_y})")
        print(f"    Size: {shape.xform.width}x{shape.xform.height}")

CLI

# Convert to SVG
visio2svg convert diagram.vsdx -o output/
visio2svg convert legacy.vsd -o output/

# Show page info
visio2svg info diagram.vsdx

# Extract text
visio2svg text diagram.vsdx

Supported Formats

Documentation

Full documentation is available at libvisio-ng.readthedocs.io.

To build docs locally:

pip install sphinx sphinx-rtd-theme
cd docs && make html

Architecture

libvisio-ng uses libvisio (C++) as an architectural reference but is a pure Python implementation. The .vsd binary parser reads OLE2 structured storage and parses Visio's chunk-based record format to extract pages, shapes, text, geometry, and styling.

License

GPL-3.0-or-later

Author

Daniel Nylander daniel@danielnylander.se