EarChord finds the chords in any song. Drop in an MP3, WAV, M4A, or AIFF file and it returns a timed chord progression, the key, and the BPM. It's free and unlimited, needs no account, and analyzes the audio in your browser, so the file never leaves your device. It detects major and minor triads, so use it to check your ear, not as a full transcription.

cut.audio is a free set of browser-based audio tools: cut, trim, join, mix, convert, and record, all without uploading your files. Everything runs on your own device, with no signup, no ads, and no watermark. Handy for trimming a vocal take, joining podcast segments, or pulling a sample.

TAIL's Sample Chopper lets you drop in any sound, slice it on the waveform, and play the chops on 16 pads, then build a pattern with the step sequencer. It runs right in your browser with no install and no signup, so the chop-and-flip lesson is one link away.

Online Omnichord brings the classic Omnichord, the 1980s electronic autoharp-style instrument, into your browser. Play chords straight from your computer keyboard and make music instantly. It's free, open-source, and needs no account. Note: chords are played with the computer keyboard, so it works on Chromebooks and laptops but not on touch-only tablets.

Masteringo's free Music Analyzer shows a track's BPM, musical key, Camelot code, spectral balance, and loudness. Drop in a file and it's analyzed in your browser, with no upload and no account. Great for DJ workshops: have students count the beat and guess the key by ear, then check their answers.