Free online music tools.

Music tools that don't need a desktop install or an account.

The Web Audio API and WebAssembly have made it possible to do studio-grade audio editing entirely in the browser - the same DSP techniques that power Audacity, Pro Tools, and Ableton, just running in JavaScript instead of compiled C. LazyTools' music tools take advantage of this to deliver real audio editing, tuning, and analysis without any download, install, or sign-up. Drop a file in, edit, export. Your audio stays on your device the whole time.

The catalogue is organised into five working groups. Tempo & timing covers the metronome, tap-tempo for finding BPM by ear, and automatic BPM detection from an audio file. Cut, join & arrange handles the sample-editing workflow - trim a clip, join multiple takes, make a ringtone, or merge tracks with crossfade. Effects & processing covers the transformations that need real DSP - independent pitch and tempo control, normalisation, reverse, and slow-down for music transcription practice. Tuners & instruments includes microphone-based tuners for guitar/bass/ukulele, a tone generator, a virtual piano, and a step-sequencer drum machine. Theory & analysis rounds it out with chord progression and circle of fifths references plus spectrum analyzer and waveform visualiser.

Why is there a separate Pitch Shifter and Tempo Changer?

Because changing one without the other is harder than it sounds. A naive speed change shifts both pitch and tempo together (think of speeding up a tape). To change pitch independently of tempo - or vice versa - you need a phase vocoder: an FFT-based technique that splits audio into overlapping frames, transforms each frame to the frequency domain, manipulates frequencies (for pitch) or time-stretches frames (for tempo) without re-pitching, and resynthesises. The Pitch Shifter is for transposing a song to a different key without slowing it down. The Tempo Changer is for slow-down practice, audiobook speed-up, or matching tempo for a mashup. The Audio Speed Changer for Learning is the simpler "both together" version, optimised for transcription practice.

How accurate is the microphone-based guitar tuner?

Within 1-2 cents - a hundredth of a semitone - on a clean signal in a quiet room. That's far more precise than your ear can distinguish unless you're tuning unisons (two strings to the same pitch, where beating becomes audible at differences smaller than 1 cent). The tuner uses pitch detection via FFT and autocorrelation against the standard A=440Hz reference, with the option to switch to A=432Hz, A=442Hz, or any other reference frequency for ensembles or historical-instrument tunings. The main accuracy challenges are background noise, room reverb, and very low strings (low B and below); a quiet room and a strong, clean pluck give the most stable reading.

What can I learn from the spectrum analyzer?

A real-time spectrum analyzer shows the frequency content of audio - how much energy is at each frequency band. Useful for: checking your room acoustics (clap and look at the decay across frequencies), identifying problem frequencies in a mix (a buzz at 60Hz suggests electrical hum; a peak around 250Hz often indicates muddy bass), tuning by ear with visual feedback, or just learning what different instruments and voices look like across the spectrum. The analyzer uses a 2048-bin FFT updated 30 times per second - smooth enough to follow musical content, fast enough to catch transients.

Is the chord progression library exhaustive?

It covers the most common progressions used in popular music across major and minor keys: I-V-vi-IV (the "axis of awesome" pop progression), ii-V-I (the jazz cornerstone), I-IV-V (12-bar blues structure), vi-IV-I-V (the "sensitive female chord progression"), and dozens of others including modal interchange and secondary dominants. Each progression is shown with its Roman numeral notation, the actual chord names in the selected key, and a play button to hear it. It's not a full music theory textbook, but it covers the progressions that most pop, rock, jazz, and folk songwriting actually uses. For deeper theory, the Circle of Fifths Tool helps you understand key relationships and modulation.

What about copyright when editing audio I didn't make?

The tools don't care - they just process whatever audio you load. Whether what you do with the result is legal depends on the source and your use. Personal listening, transcription practice, music education, and fair-use editing are typically fine. Distributing modified copyrighted material without a licence is not. The Ringtone Maker is convenient, but using a 30-second cut of a copyrighted song as your ringtone is technically a copyright issue - though one rarely enforced in practice. When in doubt, use audio you have rights to (your own recordings, public domain, Creative Commons) or get a licence.