Daniel Nylander.se

Etikett: libvisio-ng

  • Visio Viewer: A Chrome Extension That Opens .vsdx Files — No Visio Required

    Visio Viewer: A Chrome Extension That Opens .vsdx Files — No Visio Required

    Ever received a .vsdx file and had no way to open it? Microsoft Visio is expensive, Windows-only, and most online converters want you to upload your diagrams to some random server. There had to be a better way.

    So I built one: Visio Viewer, a Chrome extension that renders Visio files directly in your browser. No cloud. No uploads. No Visio license. Everything runs locally.

    What It Does

    Drop a .vsdx file onto Chrome (or use the file picker), and you get a clean SVG rendering of your diagram. The viewer supports:

    • Multi-page navigation — browse all pages in a Visio document
    • Zoom & pan — scroll to zoom, drag to pan, fit-to-page button
    • Dark mode — because of course
    • URL interception — click a link to a .vsdx file and it opens in the viewer automatically
    • Open from URL — paste a URL to a remote .vsdx file
    Network diagram with hundreds of nodes rendered in Visio Viewer
    A large network overview diagram — zoomed out to 23%, all rendered client-side
    BPMN diagram rendered in Visio Viewer
    A BPMN sample diagram with colored shapes and connectors
    MikroTik switch diagram rendered in Visio Viewer
    A detailed MikroTik CRS312 switch stencil — rendered as crisp SVG

    How It Works

    Under the hood, the extension uses libvisio-ng — a pure Python Visio parser I built — running inside Pyodide (a full CPython compiled to WebAssembly). The entire pipeline runs in a sandboxed iframe:

    1. The extension intercepts .vsdx files (via drag & drop, file picker, or URL)
    2. The file is passed to libvisio-ng running in Pyodide (Python in WASM)
    3. libvisio-ng parses the OPC/XML structure and produces SVG output
    4. The SVG is rendered in the viewer with zoom/pan controls

    All processing happens locally in your browser. No data leaves your machine. It works completely offline once installed.

    Simple Visio diagram showing Hello World
    Even simple diagrams render cleanly

    Installation

    Version 1.2.0 is available now:

    To install from GitHub: download the release, unzip, go to chrome://extensions, enable Developer mode, and click ”Load unpacked”.

    Open Source

    The extension is open source under MIT/GPL. Contributions welcome.