Getting Started

Package requirements

To create a project that uses the CEF package, add the right compiler-package reference to your project. The package ships in three flavours — one per supported Chromium version — and you pick exactly one:

Reference Chromium baseline Supported OS
twinBASIC - Chromium Embedded Framework Package v49 Chromium 49 Windows XP+
twinBASIC - Chromium Embedded Framework Package v109 Chromium 109 Windows 7+
twinBASIC - Chromium Embedded Framework Package v145 Chromium 145 Windows 10+

Use v145 unless you specifically need to support older operating systems. The package source compiles against all three — picking the reference sets the CEF_VERSION compiler constant, which selects the matching API surface.

Add the reference through Project → References (Ctrl-T) → TWINPACK PACKAGES. Tick the desired CEF package, close the dialog, and restart the compiler. Once added, CefBrowser appears in the form-designer toolbox.

Warning

Older Chromium versions should not be used for browsing untrusted content from the public Internet — they carry unpatched security vulnerabilities. v49 and v109 remain appropriate for tightly controlled environments where the browser loads only trusted local or internal content; for general web browsing, use v145.

Downloading the runtime

Unlike WebView2, CEF does not rely on a system-installed runtime. The Chromium binaries (libcef.dll and friends) ship as a separate download and must be installed alongside the application — both during development and at deploy time.

Download the runtime ZIP that matches both the CEF version and the application bitness:

Version Win32 Win64
v49 cefRuntime49_win32.zip cefRuntime49_win64.zip
v109 cefRuntime109_win32.zip cefRuntime109_win64.zip
v145 cefRuntime145_win32.zip cefRuntime145_win64.zip

See CEF Runtime Releases for the full version list and release notes.

Extract the ZIP into %LocalAppData%\twinBASIC_CEF_Runtime\. The version-stamped folder inside the ZIP — for example 145_0_7632_160_Win64 — must land directly under that path, containing libcef.dll and its sibling files:

%LocalAppData%\twinBASIC_CEF_Runtime\145_0_7632_160_Win64\libcef.dll
%LocalAppData%\twinBASIC_CEF_Runtime\145_0_7632_160_Win64\chrome_elf.dll
%LocalAppData%\twinBASIC_CEF_Runtime\145_0_7632_160_Win64\…

At startup, CefBrowser searches this default location automatically. If libcef.dll cannot be found, the Error event fires with the exact path that was searched.

To point at a different folder — for example a portable side-by-side deployment shipped with your installer — assign EnvironmentOptions.BrowserExecutableFolder during the Create event:

Private Sub CefBrowser1_Create()
    CefBrowser1.EnvironmentOptions.BrowserExecutableFolder = _
        App.Path & "\cef145_win64"
End Sub

Bitness must match

The runtime bitness must match the application bitness — a 32-bit twinBASIC build needs the Win32 runtime, a 64-bit build needs the Win64 runtime. Mixing them produces a libcef.dll load failure surfaced through the Error event.

Create a CefBrowser control on a form

With the package reference and runtime in place, CefBrowser is available in the form-designer toolbox. Drop it onto a form like any other control:

Private Sub Form_Load()
    CefBrowser1.Navigate "https://www.twinbasic.com"
End Sub

The control starts up asynchronously — the first user-visible event is Ready, which fires once the helper browser process has launched and IPC has connected. Navigation, scripting, and most property accessors raise “CefBrowser control is not ready” (run-time error 5) before then.

CefBrowser control properties

Toggle the Properties pane to see the design-time-visible surface: DocumentURL (the initial URL the control auto-navigates to once Ready fires), ZoomFactor, UserAgent, and the standard rect-dockable surface (size, Anchors, Dock).

For the full reference, see the CefBrowser class reference; for what the underlying Chromium runtime supports, consult the Chromium Embedded Framework documentation.

Samples

If you prefer to start with a sample, Sample 1b — Chromium Embedded Framework Examples is available in the new-project dialog. It mirrors Sample 1a — WebView2 Examples almost feature-for-feature, with the differences called out where the CEF package doesn’t yet expose a WebView2 equivalent.

Where next