Privacy policy

Updated 6 October 2026

Blackletter is a private, invite-only app for friends to log, rank and talk about books. This page says what it keeps about you, who can see it, and how to take it back.

What Blackletter keeps

Your account: your name, your handle, the phone number your invite was sent to, and the identifier Sign in with Apple gives the app. Blackletter doesn't ask Apple for your email address and never sees your Apple ID password.
What you add: your photo and bio, and the books you log, rank, review, quote, list, want to read or are reading, with your progress, goals, recommendations, comments, likes, blocks and reports.
Finding friends: if you let the app look through your contacts, it sends one-way hashes of their phone numbers, never names, and the server compares them with members. For contacts who haven't joined yet, Blackletter keeps a scrambled fingerprint of each, never the number, so it can tell you when they join. A fingerprint is deleted when that person joins or when you delete your account. Which members are in your contacts is worked out on your phone, not kept on the server. When you join, members who have your number are told that you joined.
If you turn off "Tell me when contacts join" in Settings, the fingerprints kept for you are deleted and nothing is kept from then on. Either way, the server counts how many numbers you checked each day, and forgets that after two days.
Notifications: if you allow them, your device's push token.
Goodreads imports: the file you upload is matched to books and becomes your entries. Source details for imported or skipped rows are cleared. Unfinished rows stay available so you can resume the import and resolve unmatched books. Import history, including which rows were imported or skipped, stays until you delete your account so uploading the same file does not add duplicate reads.

What it doesn't do

No ads, no tracking across other apps or websites, no analytics services, and your information is never sold or shared with anyone for their own use.

Who sees what

Your friends in Blackletter see your reading: rankings, reviews, diary, shelves, passages and lists. Other members see only your name, handle, photo, who invited you and friends you share. Book pages show an average score across everyone, never who gave it.

Services Blackletter runs on

Cloudflare hosts the app's server, database and photos, and processes network information such as IP addresses to deliver and protect it.
Apple provides Sign in with Apple and delivers notifications.
Hardcover supplies book search, details and covers. Searches are sent from Blackletter's server; book covers load straight from Hardcover, which sees your device's network address when they do.
Open Library (the Internet Archive) supplies book details when Hardcover doesn't have them. Searches are sent from Blackletter's server; book covers load straight from Open Library, which sees your device's network address when they do.
Expo delivers app updates. When the app checks for one, Expo sees your device's network address, the app's version and a random ID the app makes when it's installed, which isn't linked to your account.

How long it's kept

Everything stays until you delete it or your account. Deleting your account in Settings erases your account and everything you made, straight away. The owner account has no self-service deletion; see account and club-closure help. Sign-ins expire after 180 days without use, and read notifications are cleared after 180 days. Reports are kept as a moderation record, without the link to accounts that are gone. If the owner removes a member for breaking the community rules, only a one-way hash of their phone number and Apple ID is kept, so they can't rejoin.

Your choices

Change your name, bio and photo, and which notifications you get, in Settings.
Turn "Tell me when contacts join" on or off in Settings; off deletes the numbers kept for it.
Use Settings → Export my data to download your profile and photo, reading data and goals, comments and recommendation notes, social connections and actions, invitations, import history and connection metadata as JSON. It excludes sign-in credentials, private invite codes and other members’ writing.
Delete a member account with Settings → Delete account. For owner-account closure, contact support.
Block anyone from their profile or a post's ••• menu.

Children

Blackletter isn't meant for children under 13 and doesn't knowingly keep information about them.

Changes and questions

If this policy changes, this page and its date will too. For questions or requests about your data, email support@useblackletter.com.