In short: Playlist Checker has no database and no accounts. Everything it needs stays in your browser.
Your browser’s local storage keeps your settings: the Spotify Client ID, your Last.fm username and API key, your Spotify session, your language and theme, the setup progress and, for a day, the tracks you selected. Your browser’s database keeps Last.fm answers for up to a week and your playlist list for a quarter of an hour, so repeated checks are fast. During sign-in, the tab keeps two one-time check values.
Spotify is contacted directly from your browser. Last.fm is contacted through this site’s server, because Last.fm does not accept calls from web pages. Those requests carry your Last.fm API key and username and the artist, track and album names being checked; the server passes them on, returns the answer and keeps nothing.
The site is hosted on Cloudflare, which processes technical request details such as your IP address to deliver it, under its own privacy policy.
There are no analytics, no trackers, no advertising and no cookies.
A settings file you save contains your keys. Keep it private.
Sign out ends your Spotify session in this browser and keeps your Last.fm details. To erase everything, use Reset or clear this site’s data in your browser settings. Your Spotify playlists and Last.fm history are not affected. To revoke the app’s access to Spotify, remove it under Manage apps in your Spotify account.
This site is run by its owner as a personal, non-commercial project. Questions:.
Last updated: 2026-10-02