Extensions / Key Changer

Key Changer privacy policy

Last updated: October 19, 2026

Key Changer is a browser extension that changes the musical key of the audio playing in a browser tab. It does not collect any data. This policy explains exactly what it does and why it asks for each permission.

What the extension collects

Nothing. Key Changer does not collect, sell or share personal data, browsing history, audio or usage statistics, and it sends nothing to a server. It has no accounts, no tracking and no analytics inside the extension.

How it works

When you change the key, Key Changer processes the sound of the current tab on your computer, using the Web Audio API built into Chrome. It works with the video and audio players on web pages, including YouTube and YouTube or Vimeo players embedded in other sites. The sound is never recorded, saved or uploaded.

The extension makes no network requests. All of its code comes packaged with it, including the audio engine: the open-source Signalsmith Stretch library, with SoundTouch as a fallback. Both run on your device.

What stays in your browser

• For each open tab (chrome.storage.session): the key shift and the song key you set, the site's address without the page path (such as https://www.youtube.com, never the full page address) and a few technical details the popup needs, such as whether the sound is being changed and which embedded players the page has. They are deleted when you close the tab or quit Chrome.
• Until you remove the extension (chrome.storage.local): whether you have seen the first-run tips, which embedded players you chose not to allow, and the state of the rating prompt. That state is up to five dates on which you changed the key, whether you rated Key Changer, and how many times you chose “Not now” and until when the prompt stays hidden.

None of this is synced to other devices or leaves your browser. Everything is deleted when you remove Key Changer.

Permissions, explained

• activeTab — lets Key Changer work with the current tab only after you click its icon or press one of its keyboard shortcuts. It is used to change the sound in that tab and to show the site's name in the popup.
• scripting — runs Key Changer's own audio script in that tab when you ask to change the key. On some sites the player is kept out of the page itself, so a small part of the script also runs in the page to reach it.
• storage — keeps the small amount of data listed above in your browser.

Optional access to embedded players

Key Changer does not ask for this at install. Chrome asks you only when you click “Allow access to …” in the popup on a page with an embedded YouTube or Vimeo player. The access lets Key Changer change the sound of that player and is used for nothing else. You can turn it off at any time in Chrome's extension settings.

• *://*.youtube.com/* — YouTube videos embedded on other websites.
• *://*.youtube-nocookie.com/* — YouTube videos embedded in privacy-enhanced mode.
• *://player.vimeo.com/* — Vimeo videos embedded on other websites.

Pages the extension opens

• A welcome page, once, right after you install it.
• A removal page, which Chrome opens after you remove the extension. It asks why you removed it.
• If you rate Key Changer in the popup, 4 or 5 stars open its reviews page in the Chrome Web Store, and 1 to 3 stars open a feedback page. Your rating is not added to the address and is not sent anywhere.

The welcome, removal and feedback pages are ordinary web pages hosted on GitHub Pages, and Google Fonts provides their typeface; both receive your IP address and basic browser details when a page loads. The welcome and removal pages also carry a visit counter (Umami) that counts page views.

Answers you choose to send from the removal page (a reason and an optional comment) or from the feedback page (a reason, details and, if you add it, your email address) go to the developer through Google Forms. Only what you pick and type is sent, and nothing is sent until you submit the form. The feedback page asks for an email address only in case you would like a reply.

Changes

If this policy changes, the updated version will be published at this address with a new date above.

Contact

Questions? Open an issue on GitHub.

YouTube and Chrome are trademarks of Google LLC. Vimeo is a trademark of Vimeo.com, Inc. Key Changer is an independent project and is not affiliated with or endorsed by Google or Vimeo.