Any common audio format in — clean MIDI out. WAV, FLAC, OGG and M4A are transcribed by the same tuned engine as our MP3 tool, with MusicXML and a sheet preview included.
Feeding the transcriber a lossless WAV or FLAC gives it cleaner spectra than a compressed MP3 — onsets are sharper and quiet notes survive. If you recorded the audio yourself, upload the original file rather than an MP3 export. Everything else works identically to our MP3 to MIDI converter: tuned thresholds, harmonic-ghost filtering, and honest metrics on every job.