Guides

How to Use Slow & Reverb on YouTube Music Playlists (Desktop)

2026-10-11

Using the Slow & Reverb Chrome extension on music.youtube.com: playlists and autoplay, how settings persist between tracks, building presets per mood, the desktop-only limit, and when to switch to the web editor.

A playlist is where a live slowed and reverb effect earns its keep. On a single video you could just as easily find a re-upload. On a two-hour playlist, or an album, or an artist radio that runs until you stop it, the only practical way to hear every track slowed is to apply the effect to the player itself and let the queue do the rest. That is what the Slow & Reverb for YouTube extension does on music.youtube.com.

This guide is about the playlist workflow specifically. How the effect follows the queue, what the storage permission is really for, how to build a small set of presets for different moods so you are not rebuilding a sound every evening, where the desktop-only rule comes from, and the point at which you stop wanting a live effect and start wanting a file, which is where the web editor takes over. If you are new to the extension itself, the listening guide covers the controls, and the settings guide has starting values for study and sleep.

Why YouTube Music rather than YouTube

Regular YouTube is a video site that happens to contain music. YouTube Music is a player. It has album pages, a library, artist radio, and most importantly a persistent queue at the bottom of the window that keeps going when the current track ends. The extension attaches to that player once and then every track the queue loads comes through the effect. You press play on an album and you get a slowed album, start to finish, with no further clicks.

A few differences from regular YouTube matter in practice:

• Many tracks have no video. They show album art. The extension does not care; it attaches to the media element whether or not there is a picture, so audio-only tracks are processed the same way.
• Background play works. On desktop, YouTube Music keeps playing when you switch to another tab or another window. The processing happens inside the YouTube Music tab, so it keeps going too.
• Gapless albums stay gapless. Where an album runs its tracks together, the reverb tail of one carries into the next. On a concept album that is exactly the right sound.
• The song and video toggle. Tracks that have an official video let you switch between the two. The effect follows the switch.

Setting up for a playlist session

1. Install the extension from the Chrome Web Store if you have not, and pin the icon. The install guide has the details.
2. Open music.youtube.com in a normal browser tab. Reload it if it was already open.
3. Start the playlist, album or radio you want.
4. Click the extension icon, pick a preset or set the sliders, and close the popup.
5. Leave the tab alone. Every track from here on plays through your settings.

Keep YouTube Music's own playback controls at their defaults. If the player offers a speed setting and you change it, it will stack with the extension's speed and the result will be slower than either number suggests. Do all the adjusting in the extension.

How settings persist between tracks

This is the part that makes a playlist session possible, and it is what the storage permission is for.

Each time you change a control in the popup, the extension writes the new value to Chrome's local extension storage. When the queue loads the next track, the extension reads those values back and applies them before the audio starts. The result, from your side, is that the effect simply stays on. You never see the dry version of a new track for a second before the effect kicks in, and you never reopen the popup between songs unless you want to.

The same storage holds any custom presets you create. Those are read back the same way, so a preset you saved last week is in the popup tonight.

Three things follow from how this works:

The persistence also survives a browser restart. Close Chrome tonight, open YouTube Music tomorrow, and the effect is where you left it. If you want YouTube Music to be YouTube Music again, pick the Dry preset or switch the effect off in the popup. Your other settings stay put.

The extension permissions page covers the tabs and storage permissions in detail if you want to see exactly what is stored and how to look at it yourself.

Building presets per mood

The extension applies one setting to whatever is playing. It does not know whether the next track is a ballad or a club record. On a long mixed playlist that is a limit you feel: a speed that makes a 140 BPM track feel relaxed makes a 70 BPM track feel like it is stuck.

The practical answer is two-fold. Choose playlists with a consistent tempo range, and keep a small set of presets so that switching takes one click rather than six slider moves. Something like this covers most evenings:

The last row exists already as the built-in Dry preset, so you do not need to save it. The others are starting points; adjust each by ear on a playlist you know well, then save. The built-in deep preset is close to the Late row and the built-in lighter preset is close to Day, so you may find you only need to save Study and Sleep.

Name presets by when you use them rather than by what they do. Late and Sleep are easier to reach for at midnight than 0.84x heavy and 0.82x dark.

Playlists that slow well and playlists that do not

After a few sessions you start picking playlists with the effect in mind. The ones that work:

• Mid-tempo and up-tempo genre playlists. Pop, R&B, house, trap. There is room to drop the tempo and the key without the music losing motion.
• Artist radio for a single artist. Consistent production style, consistent tempo range, one setting fits.
• Instrumental and lo-fi playlists. No vocal to smear, so reverb can go higher.
• Film scores. Barely touch the speed, add a little Space, and the result is lovely.

The ones that fight you:

• Mixed decade or mixed genre playlists. Tempo swings from track to track and one speed cannot suit all of them.
• Ballad collections. Already slow. Use 0.92x or higher, or reverb alone at 1.00x.
• Live albums with crowd noise. Reverb on applause sounds like a stadium in a bathroom.
• Spoken word and podcasts. Slowing speech makes it hard to follow; a little reverb at 1.00x is as far as you want to go.

If a track comes on that sounds wrong, nudge speed up from the popup or skip. Changing speed does not reload the track; the change is instant.

Desktop only, and why that is not changing

The extension runs on desktop Chrome and on desktop Chromium browsers such as Edge, Brave, Opera and Vivaldi. It does not run on Android, on iOS, or inside the YouTube Music apps. That is a platform rule rather than a product decision: mobile browsers and the mobile YouTube Music apps do not load extensions, so there is nowhere for it to run. Firefox on desktop does not run Chrome extensions either, though a separate add-on called Slowverb exists for Firefox.

Progressive web app installs of YouTube Music, launched from a desktop shortcut rather than a tab, may also run outside the extension's reach. If the effect does nothing in an app window, open music.youtube.com in a normal tab.

What this means in practice: your slowed playlist lives on the laptop. When you leave the desk, the effect stays behind.

When the web editor takes over

There comes a point where a live effect is the wrong tool. You want the slowed version on your phone for a run. You want to send a track to a friend. You want to post it. In all of those cases you need a file, and the extension will never produce one. It does not download, record or export, by design, and that will not change.

The web editor at slowandreverb.com is the other half. You load audio you own, apply the same control set (speed, reverb, space, bass, tone, width, presets), hear the result live, and download an MP3 encoded in your browser at 96 kbps, 32 kHz. Nothing is uploaded. It runs on phones as well as desktop. For a whole album, add every file, Select All Tracks, set once, and Download All gives you a ZIP; the batch processing guide walks through it.

A useful pattern is to audition in the extension and produce in the editor. Play an album on YouTube Music through the extension, find the settings that suit it, save them as a preset, and if you own the audio and want a file, open the editor and recreate the preset there. The audition costs nothing and tells you which songs are worth the effort. The extension versus web editor page sets the two tools side by side if you are unsure which one you need.

Two honest limits on the editor side: it exports MP3 only, and Preserve pitch changes the live preview only, so exported files keep the speed-linked pitch. For a slowed album you will listen to on headphones that is fine. For a distribution master, start from a WAV and finish in a DAW.

Open the free editor: upload MP3, WAV, AAC, OGG or FLAC, adjust speed, reverb, bass, tone, width and space, then export MP3 or a ZIP of many tracks. Everything runs in your browser.