Audio

01What it is

Audio is a music player and DJ deck that runs in a browser tab. Built on Tone.js, it moves tempo anywhere from 0.1x to 4x on one slider, shifts pitch, runs a chain of effects and drives a bank of reactive visualisers, with a queue, scratch and tape-stop. It plays LABS's four music libraries, E1 to E4, or a folder of your own files. There is nothing to install and no account.

One count needs care. The page's own description promises nine visualisers, but its panel carries eleven mode buttons, ten named “reactors” and a waveform, and its feature list says “10 Reactors” (index.html:190, 1631, 1721-1744). The description is out of date; the panel is the thing you use.

It is for listeners and hobby DJs who want to bend a track's speed and pitch, colour it with effects and watch it move.

02How it works

The whole app is one HTML file of 419,581 bytes. It loads Tone.js 14.8.49 from cdnjs and jsmediatags 3.9.3 from jsDelivr, each pinned with a Subresource Integrity hash (audio/index.html:268-276). Sound is processed in the browser's Web Audio graph through Tone.js nodes (PitchShift, BitCrusher, Reverb, StereoWidener, FeedbackDelay, Phaser, Chorus, Distortion, Compressor and Filter), with an Analyser feeding the visualisers (index.html:2910-2940). Your own folder opens through the File System Access API in read-only mode, and ID3 tags are read in the page (index.html:4118-4125, 4572).

Two details show the care taken. The tag reader is held at 3.9.3 on purpose: a comment says the 3.9.4 and 3.9.5 builds ship an empty file, and we measured 3.9.5 at zero bytes. And the E1 to E4 track lists are parsed as data, never run as code. A list must be a JSON array of paths, and it is revalidated with cache: no-cache, so an unchanged list costs a 304 rather than a fresh download (index.html:4262-4278).

03The test

Together the four lists name 3,994 paths. We did not play the music itself, because it lives on the main site and these tests contact no live estate host. Had the page followed the newest jsmediatags release, it would have loaded an empty tag reader.

04Against the field

Each comparator was read on its own site on the date shown. We credit what each does better before saying where Audio goes further.

05Where it falls short

1. The page calls itself a “Browser DAW”, but we found no microphone input, recording or MIDI in the code: no getUserMedia, MediaRecorder or Tone.Recorder.
2. It cannot save what you hear. The only download writes a track list (index.html:8405-8417), not audio.
3. Opening a folder needs the File System Access API; the page itself sends Safari and Firefox users to Chrome or Edge.
4. It needs cdnjs, jsDelivr and Google Fonts to answer before it works.

06Filing note

File underLive playback with tempo, pitch and effects; not a recording studio.

Audio is honest engineering inside a narrow brief. The supply chain is pinned and explained, the track lists cannot run code, and your files never leave your machine. If you need to record or export, Audacity and BandLab are the tools; if you want a track at half speed through reverb, with nothing installed and no sign-up, this does it in a tab.

Open Audio on labs.llc →

07Spec sheet