Sprogeny

What is Sprogeny?

Sprogeny lets you combine multiple Spotify playlists into fresh, shuffled mixes. Pick your source playlists, set the weight for each, and generate new playlists directly in your Spotify library.

How does it work?

1. Sign in with your Spotify account.
2. Add source playlists by pasting a link or selecting from your library.
3. Adjust the weight sliders to control how many tracks come from each source.
4. Hit Generate — new playlists appear in your Spotify library instantly.

Is it free?

Yes. Sprogeny is completely free to use. No premium tier, no ads, no upsells.

Do I need to create an account?

No. You sign in with your existing Spotify account — there's no separate registration or password to manage.

Will it modify my original playlists?

Never. Sprogeny only reads your source playlists and creates new ones. Your originals are left completely untouched.

How is the shuffle different from Spotify's?

Sprogeny uses a truly random shuffle. There's no "weighted shuffle" that favors popular tracks, no play-count bias, and no artificial emotional weighting. Every track has an equal chance of appearing.

Does it use AI or algorithms to pick tracks?

No. Sprogeny doesn't use algorithms or AI to decide what you hear. It pulls tracks from the playlists you choose, in the proportions you set, and shuffles them randomly. Nothing is added that you didn't ask for.

What's it good for?

• Getting deep cuts from albums instead of always hearing the hits.
• Mashing up genres you wouldn't normally combine.
• Importing your friends' playlists or official Spotify playlists and mixing them together.
• Discovering music that Spotify's algorithms don't surface well — experimental, fringe, and niche artists.

Does Sprogeny store my data?

Your session is stored in an encrypted cookie. We do not persist playlist data or track information after your session ends. A hashed (non-reversible) record of used tracks is stored to prevent duplicates across blend operations — no raw user IDs or playlist contents are kept.

Does Sprogeny track me?

Sprogeny uses a self-hosted, cookieless analytics tool to count page views. No cookies are set, no personal information is collected, and no data is shared with third parties. There are no ad networks or tracking pixels.

Is my Spotify password safe?

We never see or store your Spotify password. Authentication is handled entirely through Spotify's OAuth flow — we receive a temporary access token, never your credentials.

What Spotify permissions are requested?

Only the minimum needed:

• playlist-read-private — Read your private playlists so you can select them as sources.
• playlist-read-collaborative — Read collaborative playlists you're part of.
• playlist-modify-public — Create the new combined playlists in your library.
• playlist-modify-private — Create private combined playlists.

We do not access your listening history, saved tracks, or profile details beyond your display name.

Can I revoke access?

Yes. Visit your Spotify account apps page and remove Sprogeny at any time. This immediately revokes all access.

About

Sprogeny is a personal project built because I wanted a better way to blend playlists without manually dragging tracks around. It's built with SvelteKit, Three.js, and the Spotify Web API.

If you have questions, feature requests, or found a bug — I'd love to hear from you.