FSharp.WebUI v2.5.3

April 16, 2026 · View on GitHub

F# bindings for WebUI — use any web browser as a GUI.

Screenshot

WebUI lets applications use a real web browser as the user interface while keeping the host program lightweight. This repository contains F# bindings and helpers that integrate WebUI with .NET applications.

WebUI repo: https://github.com/webui-dev/webui

Features

  • Portable (needs only a web browser at runtime)
  • Lightweight (small library, low memory footprint)
  • Fast binary communication protocol between host and frontend
  • Multi-platform & multi-browser support
  • Uses a private browser profile for safety
  • Native runtime provided by WebUI (downloaded on first use or supplied manually)

Installation

dotnet add package FSharp.WebUI --version 2.5.3

Supported platforms & upstream assests:

  • Linux x64 → webui-linux-gcc-x64.zip
  • Linux ARM64 → webui-linux-gcc-arm64.zip
  • Linux ARM → webui-linux-gcc-arm.zip
  • macOS ARM64 → webui-macos-clang-arm64.zip
  • macOS x64 → webui-macos-clang-x64.zip
  • Windows x64 → webui-windows-msvc-x64.zip

Build commands

Library

dotnet build fsharp-webui.fsproj

Example applications

Simple example

dotnet run --project examples/simple-example
# or
dotnet build examples/simple-example/simple-example.fsproj
./examples/simple-example/bin/Debug/net10.0/simple-example

Prettier CSS example

CSS example

dotnet run --project examples/prettier
# or
dotnet build examples/prettier/prettier.fsproj
./examples/prettier/bin/Debug/net10.0/prettier

Reflection example — embeds assembly resources

Reflection example

dotnet run --project examples/reflection
# or
dotnet build examples/reflection/reflection.fsproj
./examples/reflection/bin/Debug/net10.0/reflection

Note: the examples use WebUI.Browser.Chromium by default in their sample code; change to another browser by passing a different Browser enum to WebUI.showBrowser if desired.

Tests

dotnet run --project tests/WebUITests
# or
dotnet build tests/WebUITests/WebUITests.fsproj
./tests/WebUITests/bin/Debug/net10.0/WebUITests

Usage

Simple program

open WebUI

let html = """<!DOCTYPE html>
<html>
  <head>
    <script src="webui.js"></script>
  </head>
  <body>
    <button id="myBtn">Click Me</button>
  </body>
</html>"""

[<EntryPoint>]
let main argv =
    let myWindow = WebUI.newWindow()
    WebUI.bind myWindow "myBtn" (WebUIEventHandler(fun _ -> printfn "Clicked!"))
    WebUI.showBrowser myWindow html WebUI.Browser.Chromium |> ignore
    WebUI.wait()
    0

Info

Native bootstrap (nightly)

Native binaries are not redistributed in this package. They are downloaded from WebUI nightly releases on first use/build, verified with SHA-256, and cached per user machine.

Default release tag: nightly

Cache locations:

  • Windows: %LocalAppData%/fsharp-webui/nightly/<asset>
  • Linux: ${XDG_CACHE_HOME:-~/.cache}/fsharp-webui/nightly/<asset>
  • macOS: ~/Library/Caches/fsharp-webui/nightly/<asset>

Refresh and overrides:

  • MSBuild refresh: WebUIBootstrapRefresh=true
  • Environment refresh: WEBUI_BOOTSTRAP_REFRESH=true
  • MSBuild native override: WebUINativePath=/path/to/native
  • Environment native override: WEBUI_NATIVE_PATH=/path/to/native
  • Optional tag override: WebUIReleaseTag / WEBUI_RELEASE_TAG (default remains nightly)

Bootstrap testing

./scripts/smoke-bootstrap.sh
Optional:
  • SKIP_NETWORK_TEST=1 ./scripts/smoke-bootstrap.sh to skip the nightly download/verify test.

Supported web browsers

  • Chrome
  • Chromium
  • Firefox
  • Edge
  • Safari
  • AnyBrowser (automatic selection — let the native runtime pick the best available browser)

Requirements

  • .NET 10.0+
  • A web browser (Chrome, Firefox, Edge, Safari, or Chromium)
  • Network access to GitHub releases on first bootstrap (unless using native path override)

Documentation

License

Licensed under the MIT License.