UPDATE: Lento is now on Chrome! Check out the new Firefox demo video here. Head to a tab playing a music, choose your favorite preset (or dial in your own speed, reverb and bass boost), and sit back and enjoy! Supported sites - Spotify - Apple Music - YouTube - YouTube Music - Bandcamp - Soundcloud - TikTok ... and most other sites with audio or video. If it plays in a tab, Lento will probably catch it. Known limitations - Amazon Music: speed control only. Amazon DRM currently blocks the audio processing that the reverb and bass boost functionality require. - Zen Browser: Spotify and other DRM-protected sites don't play reliably on Zen. This is likely a browser limitation, but I'll keep investigating. This is a solo project, so issues will be addressed as time allows. Your patience is appreciated! Bugs and source code See a problem? Use the bug-report button right in the popup or file an issue on GitHub. Free, forever! Lento will always be free and open-source! You will never have to pay for features here. If you'd like to support my work anyway, check out my Ko-fi! Data disclaimer Lento will never transmit your data. All music processing is done locally on your machine, and nothing is ever sent to me or anyone else.