The band steps back. You play.

Instrufilt keeps the lead vocal and mutes the band on anything playing in your browser, then puts a chord chart over the lyrics — so you can be the accompaniment. Real time, on your machine, no uploads.

Install free Star on GitHub

Coming soon to the Chrome Web Store — install from GitHub today.

Works on Chrome, Edge, Brave, Arc, Vivaldi, Opera.

instrufilt.

How it works.

Most browser tools remove the singer. Instrufilt does the opposite: the singer stays, the band drops out, and you take their place.

1
Play any tab
YouTube, Spotify Web, SoundCloud — anywhere a song plays in your browser, Instrufilt can work on it.
2
Choose what stays
Pick an isolation mode: keep the singer with the rhythm section, the singer alone, or just the melody line.
3
Follow the lead sheet
Chord symbols land above time-synced lyrics in the side panel, so you always know what to play next.

Mode	Keeps	Best for
Vocal + rhythm	Singer + kick, bass, snare	Playing along with a groove to lock to — the default
Vocal only	The singer alone	A clean reference, filtered clear of the rhythm section
Lead line	A narrow band around the melody	Picking a line out by ear

Results vary from song to song — isolation shines on standard studio mixes, less so on mono, live, or heavily-effected recordings. See what to expect.

A lead sheet that follows the song.

While the vocal plays, the side panel draws chord symbols above time-synced lyrics — the current chord big, the next change already waiting.

ChartPaper Lanterns — The MarlowesKey GCapo 2 · −2

DGTap a chord for the fingering

Meetmewherethestreetlightsleanongold

Everyborrowedchordisyourstohold

Strumitslow,thesingerknowstheway

Chords over every word
Word-synced lyrics from Karalyr, with each chord change placed on the word where it lands.
Transpose & capo
Shift the chart to the shapes you actually play — a display-only shift, with accidentals that follow the key.
Fingering diagrams
Tap the current chord for its shape, plus the next change so your hand is ready before it arrives.

Charts are detected automatically and are honest about it: the first play is marked “Listening” while the chart is built, every play after renders it up front, and low-confidence chords carry a dotted underline. How the lead sheet works.

Real-time in your browser

Isolation runs entirely on your machine in a WebAssembly AudioWorklet. No uploads, no servers, no waiting — your audio never leaves the computer.

Free, forever

All isolation modes and the lead sheet are free. Just sign in once so we can keep your settings with your account.

Open source. Always.

MIT. Inspect every line or contribute on GitHub.

Hall of Fame

The players with the most practice time on Instrufilt.

No badges earned yet — be the first.

Virtuoso · 100 hours of practice

no one yet — be the first

See the full Hall of Fame

Earn badges by racking up practice time. Anonymous players are ranked too — set a display name on your account page to put your name on your spot.

What players say.

Instrufilt is brand new — reviews from the people practising with it land here and on the Chrome Web Store once the listing is live.

Coming soon to the Chrome Web Store — install from GitHub today.

Read & write reviews

One family, whichever part you take.

Instrufilt is one of three sibling projects from Betania.io. Karafilt and Instrufilt even share one account — already signed up for one, and you're signed in to the other.

karafilt.

You'd rather sing?

Karafilt is the mirror image of Instrufilt: it removes the lead vocal from any tab so you take the microphone instead of the instrument.

karalyr.

Where the words come from.

Karalyr is the family's open, word-timed lyrics database — the reason Instrufilt's lead sheet lights up in step with the singer. Missing a song? Time it there yourself.