Privacy Policy

Last updated: August 30, 2026

HeroicGuitar ("the Extension") is a Chrome browser extension that turns a YouTube video into a practice tool: it slows it down and transposes it, loops a section, and works out the song's tempo, chords and key on your own machine.

HeroicGuitar collects no data, except feedback you choose to send

The Extension has no account and no analytics. There is no HeroicGuitar service your practice data is sent to, and none of it is sent to anyone else either. The one exception: if you open the panel’s Feedback form and press Send, what you typed — plus the extension version, your browser’s user agent, and the current video’s ID only if you tick that box — is sent to a Cloudflare Worker we operate and stored there so we can read it. Nothing is sent unless you fill in and submit that form yourself.

The only requests it makes are to YouTube, on the page you are already on

To show a song's tempo and chords the Extension reads the video's description, its caption track and its comments — the same data the page itself loads — using YouTube's own endpoints. Those requests contain nothing we added and go nowhere but youtube.com. The Extension does not access your YouTube account, history or subscriptions.

Audio analysis runs on your computer

When you press Analyze song, the Extension listens to the video as it plays in your own browser and works out the tempo, the chords and the key locally. Isolating instruments uses a machine-learning model that ships inside the extension package — it is not downloaded, and the audio it processes never leaves your machine.

What is stored, and where

Your practice state for each video — loop points, saved loops, speed, pitch and detected tempo — is saved in your browser's extension storage on this device. (The panel's position, the metronome volume and the count-in are saved the same way, but as a single setting shared across every video, not per song.) If you tick Keep on disk, the separated instrument tracks for that song are saved in this browser's IndexedDB cache, marked persistent so Chrome does not evict them, so they survive leaving the page; unticking the box deletes them, and so does removing the Extension. None of this is synced, shared or readable by us.

If you choose Continue in the Studio

The analysis and — if you kept them — the isolated tracks are handed to the HeroicGuitar web app running in the same browser, on the same computer. Nothing is uploaded, nothing is downloaded as a file, and no server is involved.

Permissions

The Extension runs only on www.youtube.com and requests only what its features need:

• storage — your settings and loops, saved locally.
• scripting — re-injecting its own panel into a YouTube tab after the Extension updates.
• offscreen — the hidden page the local audio analysis and instrument separation run in.
• unlimitedStorage — so instrument tracks you chose to keep are not evicted by the browser.
• alarms — periodic cleanup of the Extension's own temporary job records.

It does not read your browsing history and does not run on any other site.

Third-Party Services

The Extension does not integrate with any analytics, advertising, or third-party tracking services.

Changes to This Policy

If this policy changes, the updated version will be posted at this URL with a revised date.

Contact

Questions? Open an issue at github.com/enkil2003/heroicguitar.