How we rate books
Every book in Swoon Shelves gets a content rating — like a movie rating, but for books. We created this because parents, teachers, and readers deserve to know what's inside a book before committing to 400 pages.
The content ratings
We also break content down into three specific categories:
How ratings are determined
We use a layered approach that combines multiple data sources:
When available, Common Sense Media is our primary reference. They provide age ratings from professional reviewers, parent ratings from real parents, and kid ratings from young readers themselves. About 7% of our catalog has direct CSM coverage — mostly well-known titles.
Goodreads provides crowd-sourced ratings and review counts, giving us a sense of how the reading community received each book. About 89% of our catalog has Goodreads data.
We pull subject classifications, recommended age ranges, and genre tags from Open Library and publisher metadata. These tell us whether a book is shelved as Children's, Middle Grade, YA, or Adult — which strongly informs content expectations.
For the thousands of books where CSM doesn't have a review, we use an algorithmic classifier that considers genre signals (dark romance gets rated higher than clean romance), age group context (YA romance defaults to PG-13 at most), subject keywords, and CSM anchoring when available.
What we don't do
With 149,000+ titles, our classifications rely on metadata, community data, and algorithms — not individual page-by-page reviews.
A "Hard R" rating isn't a criticism. It's information. Captive in the Dark is a bestseller and it has graphic content. Both things are true.
Our system is a helpful starting point, not gospel. A book's actual content may surprise you — we always recommend checking multiple sources for titles you're concerned about.
Other classifications
Beyond content ratings, every book is tagged with:
Data sources
Improving our ratings
This is a living database. We're continuously working to expand CSM coverage, add trigger warnings from StoryGraph and DoesTheDogDie, refine our classifier with better genre and content detection, and accept community corrections.
Think we got a rating wrong? We want to hear about it. Accuracy matters more than ego.
Suggest a rating changeLast updated: April 2026