The best open source alternative to SeriesGuide is Showly. If that doesn't suit you, we've compiled a ranked list of other open source SeriesGuide alternatives to help you find a suitable replacement. Other interesting open source alternative to SeriesGuide is Tonkatsu Box.
SeriesGuide alternatives are mainly Personal Tracking Apps. Browse these if you want a narrower list of alternatives or looking for a specific functionality of SeriesGuide.
Android and iOS app for tracking TV shows and movies, managing watchlists, and syncing viewing history with Trakt.tv across devices.

Showly is a TV show and movie tracking app for Android and iOS, built around a clean interface and tight Trakt.tv integration. It's aimed at anyone who wants a single place to manage what they're watching, what they've watched, and what's coming up next.
The core loop is straightforward: browse trending and curated titles, mark episodes and movies as watched, and build out a collection over time. Showly separates your Watchlist (things you plan to watch) from your Collection (things you've seen), which keeps your library organized without much manual effort.
Key capabilities:
The Trakt.tv integration is the standout feature for serious trackers. Trakt is a widely used open platform for logging watch history, so connecting Showly to it means your data isn't locked into a single app. You can switch clients or use multiple apps without losing your history.
With over 80,000 users, Showly has built a following largely on its interface quality. The UI is consistently cited as one of its strengths, which matters in a category where many alternatives feel cluttered or dated.
Looking for open source alternatives to other popular services? Check out other posts in the alternatives series and openalternative.co, a directory of open source software with filters for tags and alternatives for easy browsing and discovery.
Cross-platform collection manager for retro games, movies, TV shows, anime, manga, visual novels, and books with tier lists, visual boards, and import/export.

Tonkatsu Box is a free, open-source media tracker for people who want one place to manage everything they watch, play, and read. It runs on Windows, Linux, and Android, and covers a wide range of media types: retro games, movies, TV shows, animation, anime, manga, visual novels, and books.
The core idea is unified collection management. You can mix any media type into a single collection, switch between grid and list views, and track status across four states: In Progress, Completed, Planned, or Dropped. For TV shows and anime, it tracks individual episodes. Everything can be rated on a 1–10 scale with personal notes attached.
Finding titles is backed by a broad set of databases:
Beyond basic tracking, it has a few features that set it apart from a simple TV time alternative. Visual Boards let you arrange posters on a free-form canvas, add text notes and links, and draw connections between items. Tier Lists support drag-and-drop ranking into S/A/B/C tiers, and a Mood Grid lets you lay out picks on a customizable N×M board. Both export as PNG.
Importing existing data is well-covered. You can pull in libraries from Steam, Trakt.tv, RetroAchievements, MyAnimeList, AniList, and Kinorium. Sharing works through two export formats: a lightweight .xcoll file (requires internet for images) and a self-contained .xcollx package that works fully offline. Friends can import and fork your lists directly.
The app is built with Flutter and uses SQLite locally, so your data stays on your device. No account required, no cloud dependency. API keys for IGDB, TMDB, and SteamGridDB are optional; the app works without them out of the box.