Chrome extension

Extension Permissions, Explained

Why the Slow & Reverb for YouTube extension asks for tabs and storage, what each permission allows, what it never does, and how to review or remove it.

Every Chrome extension asks for permissions, and the install prompt rarely explains them. The Slow & Reverb for YouTube extension asks for two: tabs and storage. This page says exactly what each one is used for, what the extension does not do with them, how to check the permissions yourself inside Chrome, and how to remove the extension cleanly if you change your mind.

Short version: the extension needs to know which tab is YouTube so it can attach to the player, and it needs somewhere to keep your settings between videos. That is the entire use. It does not read your browsing history, it does not download anything, and there is no account. The same no-upload principle applies to the web editor, which processes your files in the browser without sending them anywhere. If you want to compare the two tools, see extension versus web editor.

The two permissions

The wording of Chrome's prompt for the tabs permission alarms people, and fairly so. Here is why it reads that way and what is actually happening.

tabs

Chrome groups several abilities under one permission. An extension with tabs can ask Chrome for the list of open tabs and their URLs. Chrome summarises that as "read your browsing history" because, in principle, an extension that watched tab URLs over time could build a history. That is the worst case the prompt is warning about.

Slow & Reverb for YouTube uses the permission for one purpose: to find out whether the tab you are looking at is a YouTube or YouTube Music page, so that the popup shows the right state and the processing attaches to the right player. It looks at the current tab when you open the popup or when a YouTube page loads. It does not keep a log of URLs, does not look at tabs on other sites beyond checking that they are not YouTube, and does not send URLs anywhere. There is no server to send them to; the extension has no backend.

storage

This one is quiet. Chrome does not even show it in the install prompt, because it only lets an extension write to its own private storage area on your machine. The extension uses it to remember your settings. When you change speed or reverb, the new value is written to local extension storage. When the next video loads, it is read back and applied. Custom presets you create go in the same place.

Nothing in storage is audio. Nothing in storage leaves your computer. Uninstalling the extension deletes it.

What the extension never does

This list is as important as the permissions. The extension does not request, and therefore cannot do, any of the following:

• Collect browsing history. No host permissions for non-YouTube sites, no logging of URLs, no analytics beacons.
• Download or save audio or video. There is no downloads permission and no code path that writes media to disk. The extension changes playback; it never makes a copy.
• Record audio. It processes the stream between the player and your speakers. The processed audio is not captured anywhere.
• Use your microphone or camera. Not requested.
• Create or require an account. There is no login, no identity permission, no sync.
• Read or modify pages outside YouTube. The content script only runs on youtube.com and music.youtube.com.
• Modify YouTube's servers or your Google account. It changes what you hear in your tab. YouTube sees normal playback.
• Phone home. The extension has no server. Updates come through the Chrome Web Store like any other extension.

The Chrome Web Store listing carries the developer's data disclosure: the extension does not collect or use your data, and data is not sold to third parties or used for unrelated purposes. The privacy policy linked from the listing says the same in longer words.

Why not request fewer permissions?

A fair question. The extension could in theory avoid tabs by only using a content script with a host permission for YouTube. In practice, the popup needs to know what the current tab is to display and change its settings, and that requires tabs or a very similar permission. Storage is the minimum way to remember anything between page loads; the alternative would be making you set the sliders every time a video changes.

We are not going to add permissions casually. If a future version needs something new, the changelog will say what and why, and Chrome will prompt you again before the update applies.

How to review permissions in Chrome yourself

Do not take our word for it. Chrome lets you see what any extension has access to.

1. Type chrome://extensions in the address bar and press Enter.
2. Find Slow & Reverb for YouTube and click Details.
3. Under Permissions, read the list. You should see the two described above and nothing else.
4. Under Site access, you can see which sites the extension can run on. You can restrict this to "On click" if you want the extension to do nothing until you press its icon, or leave it on the YouTube sites.
5. If you want to inspect what is stored, click Inspect views next to the service worker or background entry, open the Application tab in the developer tools that appear, and look under Storage. You will find a handful of numbers for your settings and any presets, and nothing else.

Edge, Brave and other Chromium browsers have the same page under edge://extensions or brave://extensions.

How to turn it off or remove it

You do not need to uninstall it to watch something normally. Open the popup and switch the effect off, or select the Dry preset.

To disable without removing: go to chrome://extensions and flip the toggle on the extension's card. Settings stay in storage, so re-enabling brings them back.

To remove entirely: on the same page click Remove, then confirm. Chrome deletes the extension and everything in its storage area. There is nothing on a server to clean up, because nothing was ever sent to one.

How this compares with the web editor's privacy

The web editor at slowandreverb.com follows the same principle in a different setting. You load audio files, the browser decodes and processes them with the Web Audio API, and the MP3 is encoded in a web worker on your machine. The files are never uploaded. Custom presets in the editor are saved in the browser's local storage for the site, which is the web equivalent of the extension's storage permission. You can disconnect from the internet after the page loads and the editor keeps working, which is the simplest proof that nothing is leaving.

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.