MP3 to BFSTM Converter

Convert MP3 to BFSTM format for Wii U and Nintendo Switch. Free online tool — no sign-up required. High quality audio output.

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Drop your MP3 here or click to upload
Supported: mp3
Free, No Sign-up, Browser-based

Convert MP3 to BFSTM for Wii U and Switch Custom Music

Turn your MP3 music into BFSTM files for use with Nintendo Switch and Wii U games. Our browser-based converter handles everything without any software installation.

Converting MP3 to BFSTM opens up custom music possibilities for modern Nintendo consoles. Whether you are modding Super Smash Bros. Ultimate with custom tracks or creating your own Switch homebrew soundtrack, our tool makes it easy.

Why Convert?

  • Add custom music to Super Smash Bros. Ultimate mods
  • Create custom soundtracks for Mario Kart 8 Deluxe
  • Build BFSTM music packs for Cemu (Wii U emulator)
  • Use with Nintendo Switch homebrew and custom firmware
  • Leverage BFSTM's superior audio quality over BRSTM

Supported Platforms

  • Nintendo Switch (Atmosphere / homebrew)
  • Wii U (homebrew / Cemu)
  • Cemu Emulator
  • Yuzu / Ryujinx Emulators

How to Convert — 3 Easy Steps

1

Upload Your MP3 File

Drop your MP3 file onto the tool. It will be decoded locally in your browser.

2

Select Output Format

Choose between BFSTM for Wii U or BFSTM for Switch. Configure channels and loop points.

3

Convert & Download

One click and your BFSTM file is ready to download and use.

BGM Box vs Traditional Tools

FeatureBGM BoxTraditional Tools
Sign-up RequiredNo — use instantlyOften required
InstallationNone — works in browserMust download & install
Loop Point EditingVisual waveform sliderManual hex editing
Multi-format SupportBRSTM, BCSTM, BFSTMUsually single format
Cost100% FreeFree but complex setup
PlatformAny device with a browserWindows-only tools

Supported Games

These games and emulators support custom BRSTM/BCSTM/BFSTM audio files:

Super Smash Bros. Ultimate
Mario Kart 8 Deluxe
Breath of the Wild
Super Mario Odyssey
Splatoon 2 / 3
Animal Crossing: New Horizons
Switch Homebrew

Frequently Asked Questions

BRSTM is for Nintendo Wii, BCSTM for Nintendo 3DS, and BFSTM for Wii U and Nintendo Switch. They share the same basic audio structure but differ in codec support and header format. BFSTM is the newest format and supports higher quality audio codecs.

Loop points define a range in the audio that repeats seamlessly. When playback reaches the loop end sample, it immediately jumps back to the loop start sample. This allows game music to play continuously without gaps or restarts. BGM Box provides a visual waveform slider for precise loop point editing.

Yes! BGM Box supports up to 8 channels. Multi-channel BRSTM files allow you to store multiple stereo tracks in a single file. This is commonly used in games with dynamic music systems that switch between different mixes depending on gameplay situations.

There is no hard limit, but very large files (>50MB) may take longer to process since everything runs in your browser. For best performance, we recommend files under 50MB.

No! All audio processing runs locally in your browser using WebAssembly technology. Your files never leave your computer. We value your privacy and security.