Free online MP3 to NBS converter

Minecraft note-block editors and playback tools require NBS song data instead of recorded audio when you want to recreate an MP3 as an in-game arrangement. The conversion is therefore a transcription workflow: audio is analyzed into MIDI notes, then imported and edited as NBS.

What the MP3 format is

MP3 is a lossy compressed audio format used for music, podcasts, voice recordings, game audio, and downloaded sound. Phones, media players, browsers, audio editors, digital audio workstations, and CD-ripping software commonly create or play MP3 files.

An MP3 contains an encoded audio waveform, not discrete pitches, note timings, instruments, or note-block assignments. A normal audio transcode cannot produce an accurate NBS file; the recording must first undergo audio-to-MIDI transcription.

What the NBS format is

NBS is the song format used by Note Block Studio and compatible Minecraft note-block tools. It stores timed note events, pitches, instrument assignments, tempo, and song metadata for editing or playback as a note-block arrangement.

NBS data is editable and usually much smaller than recorded audio because it describes events rather than sound. It cannot preserve vocals, effects, realistic instrument timbres, pitch bends, or the exact waveform of the MP3. NBS support and import behavior can vary between Note Block Studio versions, Minecraft tools, and playback systems.

How to convert MP3 to NBS

The dependable desktop workflow is MP3 → MIDI → NBS. Spotify Basic Pitch is a suitable local audio-to-MIDI option, and Open Note Block Studio can import the resulting MIDI and save an NBS song.

1. Prepare the audio. Trim the MP3 to the section required, and remove silence, speech, excessive noise, or reverb where possible. A solo melody or isolated instrument produces cleaner transcription than a mastered song with vocals, drums, multiple instruments, and effects.
2. Transcribe the MP3 to MIDI. Install Basic Pitch locally with pip install basic-pitch, then run basic-pitch midi-output input.mp3. The command writes a MIDI transcription to midi-output, normally with a .mid extension. Keep the original MP3 unchanged so you can repeat the transcription after preparing a cleaner excerpt.
3. Import the MIDI. Open the MIDI in Open Note Block Studio and choose File → Import → MIDI, or the equivalent MIDI-import command in the installed version. Select the generated .mid file and review the imported tracks, tempo, channels, and note density.
4. Correct the arrangement. Delete false notes, unwanted percussion, and unsuitable tracks. Set or correct the tempo, map MIDI instruments to Minecraft note-block instruments, transpose notes outside the usable range, and simplify dense chords or rapid passages. Audio transcription often needs manual editing before it is playable.
5. Save the NBS file. Use File → Save as and choose the .nbs extension. Open the saved file in the intended editor, Minecraft mod, playback tool, or schematic-export workflow to verify compatibility.

For a no-install attempt, you can upload the MP3 to the MP3-to-NBS converter on 101convert.com and download the generated .nbs file. A local tool such as Basic Pitch is preferable for private recordings because the audio does not need to leave your computer.

Quality and compatibility limits

This is an estimated transcription, not a lossless conversion. MP3 contains continuous audio, while NBS contains discrete note events, so the result cannot reproduce the original recording exactly. Chords, drums, vocals, changing instruments, background noise, reverb, and effects can create missing or false notes.

Basic Pitch and similar tools may detect overlapping notes or multiple tracks, but the NBS editor still has to map them to Minecraft's limited pitch range and instrument set. Notes that are too high or low may need transposition or removal, and excessive simultaneous notes may need simplification. Rubato and unclear beats can also cause tempo or timing errors.

If an original MIDI file is available, import it instead of transcribing the MP3. MIDI already contains note pitches and timings, avoiding the largest source of conversion errors.