Bluetooth audio transmitter for Windows. It turns an ordinary Bluetooth adapter, a cheap USB dongle or on many laptops the built-in one, from the basic codecs Windows gives it into a Hi-Fi transmitter: LDAC, LHDC V5 and aptX Adaptive at up to 96 kHz (LHDC V5 up to 192 kHz), plus AAC, SBC XQ and aptX. Windows itself offers none of the first three. BlueCaster sets the adapter up by itself and gives it back to Windows with one click (how it works).

Download (installer -setup.exe or -portable.zip) | Documentation

✅ supported · 🔧 developer mode only · ❌ not supported

• Windows 10 (22H2) or 11, x64 or ARM64 (ARM64 and Windows 10 not yet tried on real hardware)
• A USB Bluetooth adapter for BlueCaster. A separate dongle is recommended: a built-in adapter works too if it is a USB device (as in many laptops), but Windows then has no Bluetooth of its own while BlueCaster uses it. See Recommended Adapters and the verified hardware.

Windows loads only kernel drivers signed through Microsoft, which requires an EV code signing certificate (several hundred US dollars a year, usually only for companies). BlueCaster instead puts the adapter on Microsoft's own signed WinUSB driver and runs the Bluetooth stack in user mode. If you want something simpler, commercial software with a signed driver works with the built-in Bluetooth.

1. Install: run BlueCaster-<version>-win64-setup.exe (-arm64-setup.exe on ARM64; no administrator rights needed), or extract the portable zip and run bluecaster.exe. Installing over v1 or A2DP Windows Bridge 2.0.x replaces it and keeps its settings, pairings and firmware.
2. Plug in the adapter.
3. Follow the first-run setup: choose the adapter and press Set up this adapter. It assigns WinUSB (Windows asks for administrator permission) and downloads the firmware Realtek adapters need. Then press Connect next to your headphones.
4. After that, connect from Home or the tray icon.

Warning: While WinUSB is assigned, Windows' own Bluetooth cannot use the adapter. With the built-in adapter, the PC has no Windows Bluetooth at all until you restore the driver. Adapters > Restore original driver gives the adapter back to Windows at any time, and the uninstaller offers it too.

See the Setup guide and the Usage guide. For dropouts or failed connections: Dropouts and Connection Problems.

• Codec choice: picks the best codec the headphones support, or the one you choose; ABR on LHDC V5, LDAC and aptX Adaptive
• LE Audio: LC3 to LE Audio headphones and earbuds with a Bluetooth 5.2 adapter; tested on a MediaTek MT7925 and against the Bluetooth emulator so far (details)
• Capture: all system audio, a virtual audio device (e.g. VB-CABLE), or one application
• Runs in the tray: keeps streaming with the window closed, reconnects after a lost link and after sleep
• Driver setup in the app: assigns and restores WinUSB without Zadig; headphones paired in Windows through the adapter connect without pairing again
• Headphone controls: volume sync and play / pause / next / previous
• Diagnostics: link quality, AFH (avoids your Wi-Fi channels), connection flow, log, HCI capture
• Command line: bluecaster-core.exe --cli (CLI Mode)
• Updates: daily check, updates itself
• 8 languages: English, Japanese, Chinese (Simplified / Traditional), Korean, German, French, Spanish
• Headset microphone: the headphones' microphone as a Windows microphone through a virtual audio cable such as VB-CABLE; classic devices play at call quality meanwhile, LE Audio keeps its quality (details)
• Works with third-party apps such as earbud control apps: Works With (not supported by this project)

Requirements: Rust 1.90+, Visual Studio 2022+ with the C++ desktop workload, Node.js 22 with pnpm (corepack enable), Git, PowerShell 7.

git clone --recursive https://github.com/SeiyaFunaokaJP/BlueCaster.git
cd BlueCaster
pwsh ./build.ps1                      # bluecaster.exe, bluecaster-core.exe, bluecaster-driver.exe in target/release/
pwsh ./build.ps1 -Release -Arch x64   # installer and portable zip (-Arch arm64 for ARM64)

Double-clicking build.bat runs the first command. The other switches (debug build, tests, emulator test) are listed at the top of build.ps1. See Building for the steps one by one and Architecture for how the programs fit together.

The BlueCaster source code is dual-licensed under the Apache License 2.0 (LICENSE-APACHE) or the MIT License (LICENSE-MIT), at your option. See LICENSE.

Important: The distributed programs include BTstack, whose license allows use and redistribution only for personal, non-commercial purposes ("solely for personal benefit and not for any commercial purpose or for monetary gain"). Commercial licenses are available from BlueKitchen GmbH.

Third-party libraries (BTstack, libldac, libopenaptx, fdk-aac, the LHDC V5 encoder, libopus, Tauri, SolidJS and others) are used under their own licenses: see THIRD_PARTY_LICENSES.md.