Privacy policy

This policy covers version 1.0.0 of Slowed & Reverb and applies from August 11, 2026. The same policy in more formal wording is in the project's repository.

Summary

Slowed & Reverb changes how songs sound inside your browser. It doesn't send anything to me or to anyone else. That includes your personal information, what you browse or listen to, your account details, the audio itself, page content, usage statistics and diagnostic or telemetry data. It doesn't keep a browsing history, and it doesn't connect to the internet on its own. I don't run a server for it, so I never receive anything from it.

While it's running

When you turn it on with the panel or a keyboard shortcut on YouTube, YouTube Music or Spotify, it finds the page's player and checks the few things it needs, such as whether the song is playing or paused. Then it changes the sound using your browser's built-in audio tools. The audio never leaves your browser.

It doesn't read or save your login, cookies, library, playlists, messages or payment details. YouTube, YouTube Music and Spotify still talk to their own servers as usual, under their own terms and privacy policies.

Stored on your computer

Your browser keeps three things for the extension:

your effect settings, such as speed, reverb, EQ and pan;
the color theme you picked;
the presets you saved, with their names and settings.

To turn the effect back on after you reload a page, it also keeps a short note for each tab you used it in. The browser deletes these notes when you close the tab or the browser. The technical details below list exactly what they contain.

What it never does

Use analytics, telemetry, tracking, crash reporting or advertising services.
Sell, rent, share or transfer anything about you.
Use your data for credit decisions, advertising or profiling.
Download or run code from the internet. Everything it runs is in the version the browser store reviewed.

Deleting what it saved

Delete a saved preset with the × next to its name. Reset Defaults puts every setting back. Uninstalling the extension removes everything it stored, and your browser clears the per-tab notes when you close it. There's nothing to delete on my side, because nothing is ever sent to me.

If this policy changes

If a future version handles data differently, this page and the store listings will say so before that version is released. Material changes will be disclosed as required by the browser stores.

Questions

Ask in the public issue tracker on GitHub, or email me privately at slowedandreverbsupport@proton.me. Please never include passwords or login details, and keep private account information out of public issues.

Technical details

This part is for anyone who wants the specifics, including browser store reviewers.

Session storage for reloads

For each tab where the effect was used, the browser's session storage holds the tab's identifier, the site's origin, whether the effect was on and the effect settings. It does not hold the full page URL. An entry is ignored while the tab is on a different origin. It is removed when the tab closes, when the site's access is revoked or when turning the effect on in that tab fails. The browser clears any remaining entries when the browser session ends.

Permissions

activeTab: temporary access to the current tab after you open the panel or press a shortcut on it. It is used only to start or control the audio effects on a supported page.
scripting: loads the audio code packaged with the extension into that tab.
storage: keeps the settings, theme and presets, and the per-tab session entries described above.
Optional access to open.spotify.com: lets the packaged Spotify audio code start before Spotify's player does. It is requested only when you choose to turn on Spotify support and can be revoked at any time.
In Firefox, optional access to www.youtube.com and music.youtube.com: lets the extension restore effects after a reload. Each site is requested separately the first time and can be revoked.

Installing the extension grants none of these site accesses in advance. The browser records and manages the optional ones. The extension can check whether one is granted, but it never sends that information anywhere. You can see and change all of them in your browser's extension settings.

The permissions in the Chrome version's manifest. The Firefox version also lists www.youtube.com and music.youtube.com as optional.

"permissions": [
  "activeTab",
  "scripting",
  "storage"
],
"optional_host_permissions": [
  "https://open.spotify.com/*"
]

Limited Use

Information the extension can reach through these permissions is used only to apply audio effects, which is its single purpose. It is not transferred, used for advertising or credit decisions, or made available for human review. Its use of that information complies with the Chrome Web Store User Data Policy, including the Limited Use requirements.