Chrome extension

Slow Down YouTube Videos With Reverb

Slow down YouTube videos with reverb while they play. A free Chrome extension adds speed, pitch drop and reverb controls to any video, live in the tab.

YouTube already lets you slow a video down. What it does not let you do is slow it down the way a slowed + reverb edit sounds, with the pitch dropping along with the tempo and a reverb tail filling the gaps. That is the gap the Slow & Reverb for YouTube extension fills. Install it once, open any video, and the audio in that tab plays through the same kind of effect chain you would use in the web editor, except nothing is downloaded and nothing is exported. You just listen.

This page covers how to install it, how to use it on a normal YouTube video, how it compares to YouTube's own playback speed menu, and what it will not do. If you are mostly interested in what it does to the sound, the YouTube reverb extension page goes deeper on that side. If you want to know what the two permissions are for, see extension permissions.

Install in under a minute

1. Open the extension's listing on the Chrome Web Store: Slow & Reverb for YouTube.
2. Click Add to Chrome, then confirm. Chrome shows the two permissions it asks for, tabs and storage.
3. Open or reload a YouTube video. The extension does not touch tabs that were already playing before it was installed until you reload them.
4. Click the extension icon in the toolbar to open the controls, or pin it so it stays visible.

The extension is version 0.2.1 at the time of writing and runs on desktop Chrome and other Chromium browsers such as Edge, Brave and Opera. It does not run on phones, because mobile Chrome does not support extensions. On a phone, the web editor with your own files is the route.

What slowing a YouTube video actually changes

When you pull the speed down, two things happen to the audio in the tab. The tempo drops, so the song takes longer to play. And unless you choose otherwise, the pitch drops with it. At roughly 0.84x the key falls by about three semitones. That lower key is the sound people recognise as slowed; a voice sits deeper in the chest, cymbals lose their edge, and the whole mix feels heavier.

Reverb then adds the sense of distance. The extension mixes a reverberated copy of the audio back in with the dry signal. The more you add, the further away the song seems to be. A small amount gives the impression of a large room. A lot turns the track into a wash.

The video keeps playing in sync, because the extension changes the playback rate of the video element itself and processes the audio that element produces. Captions, chapters and the progress bar all still work.

Settings that work for most videos

The controls are the same family you find in the editor: speed, reverb, space, bass, tone and width, plus presets you can save. These starting points are for listening, so they lean lighter than the settings people use for uploads. You are hearing the effect on top of YouTube's own compressed audio, which already lost some high end.

The last row is there to make a point. The extension is not only for music. A little reverb at normal speed makes a long interview feel like it is in a room instead of a laptop speaker, and it costs nothing to try.

Extension versus YouTube's playback speed menu

YouTube's gear menu has a speed setting. It is useful for lectures. For music it is a different tool, and the differences matter.

The biggest single difference is pitch. YouTube's speed control is built to keep speech intelligible, so it time-stretches the audio and holds the key fixed. A song at 0.75x in the YouTube menu sounds like the same singer performing more slowly, with some warble. The extension lets the pitch fall, which is the whole character of the slowed style. If you do want slower playback in the original key, the extension's pitch option covers that too, but the default is the classic drop.

Where it works and where it does not

It works on watch pages, Shorts, embedded players on youtube.com, playlists, and the Mix autoplay queue. It also works on music.youtube.com, which has its own page on YouTube Music slowed and reverb. When autoplay moves to the next video, the effect stays on, so a playlist becomes a continuous slowed session without you touching anything.

It does not work on YouTube embeds on other websites, because the extension only runs on YouTube domains. It does not work in the YouTube desktop app wrappers, in Firefox (a separate add-on called Slowverb exists for that), or in Safari. And it does not do anything to video that is being cast to a TV, because the audio is being decoded on the TV rather than in your tab.

Things to know before you rely on it

It changes what you hear, not what exists. The video on YouTube is untouched. Nobody else hears your settings. If you want a file you can keep or upload, that is a different job and a different tool. Process your own audio in the slowed reverb maker and export an MP3 there.

It uses a little CPU. Convolution reverb is real work. On a laptop from the last several years you will not notice. On a very old machine, or with many tabs playing, you may hear dropouts; lower the reverb or close other media tabs.

It is honest about speed limits. Below about 0.70x most vocals turn to mush no matter what tool you use. The slider will go there, but the sweet spot for songs sits between 0.80x and 0.90x. Read speed control for why.

Ads play through the effect too. The extension cannot tell the difference between the video and a pre-roll ad in the same player, so an ad will come through slowed. Most people find that funny for about one day.

A simple listening workflow

1. Pin the extension icon so it is one click away.
2. Set a preset you like at the start of a session. The storage permission keeps it for next time.
3. Queue a playlist or let a Mix run. The effect follows every video.
4. If a particular video sounds muddy, drop Reverb first, then raise Tone a couple of dB. Do not touch Speed to fix mud; it rarely helps.
5. Turn the extension off from its popup when you want to watch something at normal speed and dry. You do not need to uninstall it.

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.