Slowed
Free
Slow down your track for a dreamy, lo-fi feel.
Free · In your browser · Nothing to install
Professional audio effects at your fingertips. Add reverb, 8D audio, echo, pitch shifting and more — right in your browser.
01 / Listen before you create
Hit play and switch presets — every clip here was rendered by the same engine that processes your tracks. Real IR reverb, real time-stretching, real loudness normalization.
Interactive demo · Studio Default
KEEP EXPLORING
A taste of the library. These effects are available in the full studio.
Explore all 34 effects02 / Effect library
Every change re-renders from your original lossless master. Add, remove, combine — zero quality loss, and you can undo anything.
Slow down your track for a dreamy, lo-fi feel.
Extreme slow-down for deep, atmospheric textures.
Speed up your track for high-energy edits and remixes.
Maximum speed boost for hyperpop and nightcore edits.
Add depth and space with customizable echo delay.
12 spaces recorded in real places, from a small booth to a huge dome.
Shift the pitch down for a deeper, darker tone.
Extreme pitch-down for sub-bass and dark atmospheres.
Shift the pitch up for bright, airy sounds.
Maximum pitch-up for hyperpop and chipmunk effects.
Pan audio in a 360° soundscape for an immersive experience.
Lush modulated doubling for vocals and synthesizers.
Rhythmic pulsing amplitude and analog volume modulation.
Heavy low-end boost for massive punchy bass.
Warm vintage filter emulating analog tape and vinyl.
Bandpass filter mimicking vintage radio broadcast.
Saturated 808, lower pitch and tempo, and the mix breathing with the bass. Three variations: Dark, Drift and Tape.
Blown-out bass up front and open highs, in the style of Brazilian funk. Three variations: Heavy, Overdrive and Light.
Transform any voice into a robotic, electronic sound.
Lo-fi 8-bit digital crunch and rhythmic distortion.
Layer soothing rain sounds beneath your track.
Add dramatic thunder rumble to your audio.
Surround your track with peaceful forest ambience.
Layer calming ocean waves beneath your music.
The song playing at the party on the other side of the wall: only the bass gets through, with the room around it.
The song leaking from someone else's headphones: just the thin highs, no bass.
Inside a car with a subwoofer: swollen bass, a closed-in cabin and an almost mono image.
In the bathroom at the party: the song muffled through the door, with the tiles' echo.
Smooth adaptive volume rise at the start of your track.
Smooth adaptive volume decay at the end of your track.
Play audio in reverse for seamless transitions and reverse vocal chops.
Rhythmic digital glitch repeat and quick dynamic cuts.
Dynamic low-pass sweep with gradual top-end cut for build-ups.
Dynamic high-pass sweep filtering the bass for tension before drops.
1 track · 0:11
This diagram illustrates the workflow; use Karps Music to process a track.
03 / Studio
Upload your track, apply effects in real time and export — no software to install, no account needed to explore.
Behind the sound
Everything a producer expects, with none of the setup.
Every change re-renders from your original lossless master. Add, remove, combine — zero quality loss, and you can undo anything.
No downloads, no plugins, no updates. Any computer, any OS.
12 real spaces, from Booth to Dome — plus speed, pitch, echo, robot, 8D, chorus, tremolo, bass boost, lo-fi, phonk, funk, scenes like Another Room and Car, reverse, stutter and sweeps.
MP3 for sharing, lossless WAV for production.
Your files live in private storage, are never public, and are gone the moment you delete them.
Up to 5 tracks per project. Split, trim and arrange waves on a timeline, then export the full mix.
04 / New · Karps Radar
Market trend intelligence built right into your studio. Track official releases from your favorite artists and Top Charts across 20+ countries in real time — then take any of them into the Studio with your own audio.
Explore Karps Radar ↗A product workflow preview, not a live market feed.
Made for
05 / From file to finished sound
Three simple steps to transform your audio.
Sign up for free, create a project and upload any audio file to get started.
Browse our effects library and apply as many as you want — instantly processed.
Export your processed track and share it with the world.
06 / FAQ
No. Karps runs entirely in your browser. Upload, edit, preview and export — nothing to download.
One credit renders one track when you create a project. Free gets 3 a month, Premium 50, Pro 100 — and you can buy extra packs that never expire.
Every plan uploads MP3, M4A, WAV or FLAC: up to 5 min on Free and up to 8 min on Premium and Pro. Downloads are MP3 or M4A on any plan, plus WAV on Premium and Pro.
Yes. You can upgrade or switch plans at any time. Your data is always preserved.
Your projects remain accessible but you'll be limited to 3. No data is deleted.
Our Free plan gives you access to the core features permanently. No trial needed to start.
Ready when you are
Upload a track, add effects, and export — all in your browser. Free to start, nothing to install.
Find useful slowed + reverb settings for speed, pitch and space. Compare browser renders and real Studio rooms, then choose a clear mix for your track.
Understand Spotify loudness guidance, YouTube's documented limits, LUFS and true peaks. Check muddy edits and try Refine's account-based preview first.
Make 8D audio in your browser with real spin and reverb controls. Compare cycle speeds, export stereo MP3, and learn an honest Audacity alternative.