Guides

How to Install the Slow & Reverb Chrome Extension (Step by Step)

2026-10-11

A walkthrough of installing Slow & Reverb for YouTube from the Chrome Web Store, pinning it, using it on a first video, reading the permission prompt, and installing on Edge or Brave.

Installing a Chrome extension takes about thirty seconds, but the thirty seconds after that are where people get stuck. The icon is hidden behind a puzzle piece, the YouTube tab that was already open does nothing, and the permission prompt used a phrase that sounded alarming. This guide walks through the whole thing in order, from the store page to a slowed video playing, using the free Slow & Reverb for YouTube extension, version 0.2.1 at the time of writing.

If you already have it installed and want to know what to do with it, skip to the listening guide. If you want the long version of what the two permissions mean before you click anything, the extension permissions page has it. And if what you actually want is a slowed MP3 of a file you own, the extension is the wrong tool; the web editor does that and does not need installing.

Before you start: check your browser

The extension is built for desktop Chrome and runs in other desktop browsers based on Chromium. That covers Edge, Brave, Opera and Vivaldi. It does not run on Firefox or Safari, and it does not run on any phone or tablet, because mobile browsers do not load extensions.

If your browser is in the first five rows, carry on. If you are on a phone, the web editor works in your mobile browser with your own files, and the phone guide explains that route.

Step 1: Open the Chrome Web Store listing

Go to the listing for Slow & Reverb for YouTube. Take a second to check you are on the right page. The name should read Slow & Reverb for YouTube, the developer website should be slowandreverb.com, and the store should show the badge that says the listing was created by the owner of that website. There are other extensions with similar names. Ours is the one with that badge and that website.

The description on the listing is short: real-time speed and reverb controls for YouTube, with bass, tone, width and space controls, built-in presets, and the option to save your own. That is the whole feature set. There is no mention of downloading or recording because the extension does neither.

Step 2: Click Add to Chrome

Click the blue Add to Chrome button. Chrome opens a small dialog that names the extension and lists what it can do. For this extension the dialog will mention reading your browsing history. That line is Chrome's standard wording for the tabs permission, and it is explained in the next section. Click Add extension.

Chrome downloads the extension (it is small, under a hundred kilobytes) and shows a confirmation bubble near the toolbar. You are now installed, but nothing has changed yet in any tab that was already open.

Step 3: Understand the permission prompt

The extension requests two permissions, tabs and storage. Only one of them appears in the install dialog.

tabs is the one that produces the "read your browsing history" line. Chrome uses that phrase for any extension that can ask which tab is active and what its URL is, because in principle such an extension could keep a log. Slow & Reverb for YouTube uses it to check whether the tab you are on is youtube.com or music.youtube.com, so the popup can show the right controls and the audio processing attaches to the right player. It does not log URLs and has no server to send them to.

storage does not appear in the dialog because Chrome considers it low risk. It lets the extension keep a small private storage area on your computer, which is where your speed, reverb and other settings live between videos, along with any presets you save.

That is the complete list. No downloads permission, no microphone, no identity, no access to other websites. The permissions page shows how to confirm this yourself at chrome://extensions after installing.

Step 4: Pin the icon so you can find it

Chrome hides newly installed extensions behind the puzzle piece icon at the right end of the toolbar. If you leave it there, you will have to click the puzzle piece and then the extension every time you want the controls.

1. Click the puzzle piece icon.
2. Find Slow & Reverb for YouTube in the list.
3. Click the pin icon next to it.

The extension's icon now sits in the toolbar permanently. In Edge the same menu is under the extensions icon, which looks like a puzzle piece as well. In Brave it is the same puzzle piece. Pinning is purely for convenience and changes nothing about how the extension works.

Step 5: Open or reload a YouTube video

Go to youtube.com and start any video. If you already had a YouTube tab open before installing, reload it. Extensions attach to pages when they load, so a tab that was open before the install will not pick up the extension until it is refreshed. This is the single most common reason a fresh install appears to do nothing.

Once the video is playing, click the extension's icon. The popup opens with the controls described on the slow down YouTube videos page: speed, reverb, space, bass, tone and width, plus the presets. Pick one of the built-in presets and listen. The pitch should drop, the tempo should ease off, and a room should open up around the sound. The picture slows with the audio and stays in sync.

If you hear nothing change, work through the short list below before assuming something is broken. The full troubleshooting guide covers the longer tail.

• Reload the tab once more.
• Check that the video is playing in the normal YouTube player on youtube.com, not an embed on another site.
• Check that the effect is actually switched on in the popup and the preset is not Dry.
• Check that the browser is not muted and the tab is not muted.

Step 6: Try YouTube Music

Open music.youtube.com in the same browser and play a song. The same popup works there, and because YouTube Music runs a continuous queue, you can set the effect once and let an album play. The YouTube Music guide goes into how settings carry between tracks.

Installing on Edge

Edge installs Chrome Web Store extensions directly, but it adds one step the first time.

1. Open the same Chrome Web Store listing in Edge.
2. Edge shows a banner at the top saying you can now add extensions from the Chrome Web Store. Click Allow extensions from other stores and confirm.
3. The Add to Chrome button becomes usable. Click it and accept the prompt as above.
4. Pin the icon from the extensions menu, which in Edge is the puzzle piece next to the address bar.

Edge manages the extension at edge://extensions, which mirrors Chrome's page. Updates come through the Chrome Web Store even though you are in Edge.

Installing on Brave

Brave installs from the Chrome Web Store with no extra permission step. Two things worth knowing:

• Brave Shields blocks scripts and trackers on sites. It should not interfere with an extension, because the extension is not a site script, but if the popup opens and nothing happens on the video, try reloading the tab once with Shields down for youtube.com to rule it out, then turn Shields back up.
• Brave's extension page is at brave://extensions.

Opera users may be asked to install a small Opera add-on that enables Chrome Web Store installs before the Add button works. Vivaldi needs nothing extra.

How to update the extension

You do not have to do anything. Chrome checks the Web Store for extension updates on its own schedule and installs them in the background. The current version is 0.2.1. To see which version you have:

1. Type chrome://extensions in the address bar and press Enter (edge://extensions or brave://extensions in those browsers).
2. Find Slow & Reverb for YouTube.
3. The version number is shown on the card or under Details.

If you want to force a check rather than wait, switch on Developer mode at the top right of the extensions page and click Update. Developer mode can be switched off again afterwards. What changed in each version is listed on the changelog.

If an update ever adds a new permission, Chrome disables the extension and asks you to approve it before it runs again. The current permissions are tabs and storage, and the changelog will say if that ever changes.

How to disable or remove it

You rarely need to uninstall. If you want to watch something at normal speed, open the popup and switch the effect off or choose Dry.

To disable without removing, go to chrome://extensions and flip the toggle on the extension's card. Your settings remain in storage and come back when you re-enable it.

To remove completely, click Remove on the same card and confirm. Chrome deletes the extension and its storage area, which held your settings and presets. Nothing exists anywhere else to clean up, because the extension has no account and no server.

Install checklist

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.