Privacy Policy
Last updated: September 3, 2026
ShelfScanner takes a photo of a bookshelf and recommends books from it. This page says what the app keeps, where it goes, and for how long. There is no account, no advertising, no analytics and no affiliate link anywhere in it.
Your device
ShelfScanner sets one cookie, shelfscanner_session, the first time you open the
scanner. It holds a random token that tells your scans, preferences and reading list apart from
everyone else's; we store only a hash of it, with the time it was made and last seen. It lasts a
year. Reading this page, the terms, the contact page or the homepage does not set it. Clearing
the cookie makes you a new visitor: your reading list and preferences stay in the database but
nothing links them to you any more.
Your photo
The photo you upload is resized and stripped of its metadata (location, camera, time) before it is stored, in a private bucket that only the app can read. To read the spines it is sent to an AI model at Google (Gemini) or, if that fails, at Anthropic (Claude), under their API terms. We delete the photo itself 30 days after upload. The record of the scan stays: the titles read from it, the books recommended and why, the models used, timings and cost. Occasionally we label a photo by hand to test the app; a labeled photo is kept until we remove it.
The titles read
Each title read from your photo is sent to Open Library to check that it is a real book and to fetch its cover; Open Library sees the title, not the photo.
Your preferences
The genres and favorite authors you pick, and anything you type about what you like, are stored for your device. If you upload a Goodreads export, the file is read once and not kept; what we keep from it is up to 60 rated books (title, author, rating), up to 20 titles you want to read, and any book you marked as not finished. To choose recommendations, the titles read from your photo and your preferences are sent to an AI model at OpenAI (GPT) or, if that fails, at Anthropic (Claude), under their API terms.
Your reading list and feedback
The books you save and the picks you mark "Not for me" are stored for your device. We look at them, without knowing who you are, to see which models and prompts recommend well.
Where it runs
The app runs on Vercel and the database and photo bucket are on Supabase; both keep ordinary server logs. The page's fonts come from Google Fonts, so your browser asks Google for them and Google sees your address when it does.
Your choices
You can remove a book from your reading list at any time, and clear the cookie to start over. If you want the scans, preferences or list for your device deleted, contact us: we cannot tell which records are yours without your help, so say roughly when you scanned and what was on the shelf.
Changes
When this policy changes, the new one appears here with a new date at the top.