Waveform Viewer-compare & measure audio by Eric

Waveform Viewer turns any audio on a web page into a real waveform you can look at, compare, and measure — without downloading files into a desktop editor first.

It was built for language practice, where the whole point is comparing a model recording against your own attempt, but it works anywhere audio plays: podcasts, music tools, transcription apps, QA of your own site’s audio.

WHAT IT DOES

• Draws a waveform for every audio clip the page loads, stacked as lanes in a floating panel you can drag, resize, and pop out into its own window.

• Shares one time scale across all lanes, so two recordings line up vertically and differences in pacing are obvious at a glance.

• One-click onset alignment shifts every lane so their first audible moment starts together. You can also drag any lane sideways to align it by hand, with the exact offset shown in milliseconds.

• Plays every lane together through a single synced playhead, so you hear the comparison instead of guessing. Mute or solo individual lanes while it plays.

• Drag across the waveform to measure any interval to the millisecond — the gap between two phrases, the length of a pause, how long a word takes.

• Download what you are looking at: the selected region as a WAV file, or the original audio file untouched.

• Open audio files straight from your computer, or drag them onto the panel, so you can compare something you already have against what the page is playing.

• Open the panel as its own browser window and drag it to a second monitor, where waveforms fill the screen instead of hiding in a corner.

HOW IT FINDS AUDIO

Many players never create an

PRIVACY

No accounts, no servers, no analytics, no tracking. Audio is decoded locally in your browser and nothing ever leaves your machine. The extension makes no network requests of its own beyond re-reading the audio files the page already loaded.

Open source under the MIT license.