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Limnu alternatives · Whiteboards

Open-source alternatives to Limnu

Limnu is not described as open source on its own site. 12 of the 98 other whiteboard and mind map tools in this directory are open source, according to their own sites.

Limnu has a free plan. Paid plans start at $5 per month, billed monthly ($50 billed yearly). All of them are free or have a free plan.

12 tools · Listings checked up to Nov 13, 2026 · Where the facts come from

How each one differs from Limnu

  1. Excalidraw

    Open-source whiteboard for hand-drawn style sketches and diagrams

    • Excalidraw starts at $6 per user / month, billed annually. Limnu starts at $5 per month, billed monthly ($50 billed yearly).
    • Only Limnu lists an iOS app.
    • Excalidraw is open source, self-hostable and end-to-end encrypted, according to its own site.
    • Excalidraw also covers diagrams.
    Excalidraw vs LimnuExcalidraw pricing and details

  2. OpenBoard

    Free open-source interactive whiteboard software for classrooms

    • OpenBoard is free. Limnu starts at $5 per month, billed monthly ($50 billed yearly).
    • Only OpenBoard lists Windows, macOS and Linux apps.
    • Only Limnu lists a web app.
    • Only Limnu lists an iOS app.
    OpenBoard vs LimnuOpenBoard pricing and details

  3. draw.io

    Free diagram editor that saves files to storage you choose

    • draw.io is free. Limnu starts at $5 per month, billed monthly ($50 billed yearly).
    • Only draw.io lists macOS, Windows and Linux apps.
    • Only Limnu lists an iOS app.
    • draw.io is open source and self-hostable, according to its own site.
    draw.io pricing and details

  4. Parabol

    Retrospectives, standups and sprint poker for agile teams

    • Parabol starts at $8 per active user / month. Limnu starts at $5 per month, billed monthly ($50 billed yearly).
    • Only Limnu lists an iOS app.
    • Parabol is open source, according to its own site.
    • Parabol also covers templates and tasks.
    Parabol pricing and details

  5. Freeplane

    Free, open source mind mapping app for the desktop

    • Freeplane is free. Limnu starts at $5 per month, billed monthly ($50 billed yearly).
    • Only Freeplane lists Windows, macOS and Linux apps.
    • Only Limnu lists a web app.
    • Only Limnu lists an iOS app.
    Freeplane pricing and details

  6. PlantUML

    Draw UML and other diagrams from plain-text descriptions

    • PlantUML is free. Limnu starts at $5 per month, billed monthly ($50 billed yearly).
    • Only PlantUML lists a browser extension.
    • Only Limnu lists an iOS app.
    • PlantUML is open source, according to its own site.
    PlantUML pricing and details

  7. Flowchart Fun

    Text-based flowchart maker that draws diagrams as you type

    • Flowchart Fun starts at $2 per month (billing basis not stated). Limnu starts at $5 per month, billed monthly ($50 billed yearly).
    • Only Limnu lists an iOS app.
    • Flowchart Fun is open source, according to its own site.
    • Flowchart Fun also covers mind mapping and diagrams.
    Flowchart Fun pricing and details

  8. WiseMapping

    Free open-source online mind mapping with a self-hosted option

    • WiseMapping is free. Limnu starts at $5 per month, billed monthly ($50 billed yearly).
    • Only WiseMapping lists macOS, Windows and Linux apps.
    • Only Limnu lists an iOS app.
    • WiseMapping is open source and self-hostable, according to its own site.
    WiseMapping pricing and details

  9. Markmap

    Free open-source tool that turns Markdown outlines into mind maps

    • Markmap is free. Limnu starts at $5 per month, billed monthly ($50 billed yearly).
    • Only Limnu lists an iOS app.
    • Markmap is open source, according to its own site.
    • Markmap also covers Markdown, mind mapping and diagrams.
    Markmap pricing and details

  10. Structurizr

    Open-source models-as-code tool for C4 architecture diagrams

    • Structurizr starts at £300 per month for up to 20 unique users, per server installation. Limnu starts at $5 per month, billed monthly ($50 billed yearly).
    • Only Limnu lists an iOS app.
    • Structurizr is open source and self-hostable, according to its own site.
    • Structurizr also covers diagrams.
    Structurizr pricing and details

  11. Pencil Project

    Free open-source desktop tool for GUI mockups and diagrams

    • Pencil Project is free. Limnu starts at $5 per month, billed monthly ($50 billed yearly).
    • Only Pencil Project lists macOS, Windows and Linux apps.
    • Only Limnu lists a web app.
    • Only Limnu lists an iOS app.
    Pencil Project pricing and details

  12. nomnoml

    Text-to-UML diagram editor with a live preview

    • nomnoml is free. Limnu starts at $5 per month, billed monthly ($50 billed yearly).
    • Only Limnu lists an iOS app.
    • nomnoml is open source, according to its own site.
    • nomnoml also covers diagrams.
    nomnoml pricing and details

Common questions

Is there an open-source alternative to Limnu?

Yes. Excalidraw, OpenBoard, draw.io, Parabol, Freeplane, PlantUML, Flowchart Fun, WiseMapping and 4 more are open source, according to their own sites.

Is Limnu open source?

Limnu is not described as open source on its own site. The listing was checked on Nov 12, 2026 against the pages it cites.

When was this checked?

Each listing shows its own date. On this page they run from Oct 5, 2026 to Nov 13, 2026. Vendors change prices and plans without notice, so confirm on their site before you buy.

This page is built from the listings. A tool is here because its listing says so, and the order is how close each is to Limnu: the alternatives its listing names first, then the tools that share the most features with it.