Audio utilities
23 tools for a sound, each in your browser on an open-source audiojs package. Nothing is uploaded.
Convert
- Audio converterMP3, WAV, FLAC, M4A, ALAC, WavPack, OGG, Opus, AAC, AIFF, CAF, WebM, QOA; reads APE, TTA, Musepack, DSD, tracker modules too
@audio/decode,@audio/encode,@audio/resample - Extract audio from videoVideo → MP3, WAV, FLAC, M4A, ALAC, OGG, Opus, AAC
@audio/decode,@audio/encode - Remove or replace video audioStrip the audio track, or swap in AAC, Opus, ALAC or FLAC — the video is never re-encoded
@audio/encode-mp4,@audio/decode,@audio/encode - MIDI to MP3Render a MIDI file with a synth-GM instrument set, no soundfont
@audio/midi-render,@audio/midi-parse - Audio to MIDI converterSongs, chords, piano, guitar or voice to MIDI, MusicXML and ABC, with Spotify’s Basic Pitch
@spotify/basic-pitch,@audio/mir,@audio/beat,@audio/midi,@audio/musicxml,@audio/midi-render
Measure
- Loudness meter and normalizerLUFS, true peak, loudness range; normalize for Spotify, YouTube, podcasts
@audio/loudness,@audio/dynamics - Lossless audio checkerDetect a fake lossless FLAC or WAV: spectral cutoff, edge sharpness, spectral holes
@audio/measure-lossy - Key and BPM finderMusical key, Camelot code, tempo, chords
@audio/mir,@audio/beat - TunerChromatic tuner for guitar, bass, violin, voice
@audio/pitch,@audio/note,@audio/mic - SpectrogramFrequency-over-time image of any recording
@audio/stft,@audio/spectral - Room and speaker measurementFrequency response, reverb time (RT60), latency, via a sine sweep
@audio/measure,@audio/synth,@audio/mic - Audio latency testRound-trip delay from speaker to microphone, and the Bluetooth delay you hear
@audio/synth-chirp
Clean up
Edit
Separate
- Vocal removerKaraoke track or isolated vocal, by a trained model (SCNet, Mel-Band RoFormer) or mid/side
@audio/neural-separate,@audio/vocals - Stem splitterVocals, drums, bass and other from any song, by the SCNet model; play, mute, solo, rebalance, save
@audio/neural-separate,@audio/decode,@audio/encode
Voice
Make
- MetronomeA click from 20 to 300 BPM: tap tempo, accents and muted beats, subdivisions, nine sounds
web-audio-api - Audio recorderRecord from the microphone, save as MP3, WAV, FLAC, Opus
@audio/mic,@audio/encode - Tone generatorSine, square, sawtooth and triangle tones, binaural beats, harmonics, noise, sweeps; save as WAV
@audio/encode
Why these run on your device
audiojs is a set of JavaScript and WebAssembly packages for decoding, encoding, measuring and processing audio. The same packages power these pages: @audio/decode reads the file, the tool's package does the work, @audio/encode writes the result. No server sees your audio, so there is no size limit, no queue and nothing to delete. Every page links the package it demonstrates; the code is on GitHub and npm.