Last updated: 16 October 2026
HoppingBooks lets people give away books they have finished with. The person receiving a book pays the postage and a small fee; the book itself is free. To post a parcel we need somewhere to send it, so this service cannot work without handling some personal data. This page explains exactly what we hold, why, who else sees it, and what you can ask us to do.
The controller for the data described here, in the sense of the GDPR, is:
Eric Braun e Silva Nordstrandring 7 22926 Ahrensburg Germany Email: hello@hoppingbooks.com
Write to that address for anything on this page, including any of the requests described under Your rights.
Your account. Your name, email address, and — if you sign in with a password — that password stored only as a bcrypt hash, never as text we can read. Optionally a profile photo and a short bio, if you add them. We need this to know who you are and to let you back in.
Signing in with Google. If you choose Continue with Google, Google tells us your email address, that Google has confirmed it, and your name. We keep only your first name as your account name, which you can change in your profile, and we do not take your Google photo. Google learns that you use HoppingBooks; what Google does with that is in Google's own privacy policy. You can always sign in with an email link instead.
When scanning or listing a book goes wrong. If the camera will not open, reads nothing until you close it, reads an ISBN no catalogue knows, a cover photo finds nothing, or a book cannot be saved, we note what happened so we can fix it: the kind of problem and its reason, the ISBN if there was one, the title and author read from a cover photo, which barcode reader ran and for how long, the picture size the camera gave, and your browser and device type. Never a picture from the camera. It is kept with your account for 90 days and then deleted. The legal basis is our legitimate interest in a scanner that works (Art. 6(1)(f) GDPR).
Your postal address. Street, city, postcode, any state or region, and country. We need it to work out what postage will cost and to get a parcel to you or from you.
Pickup and “near you”. If you offer pickup, readers see the town of the address your books are listed from, and how far away it is, rounded to whole kilometres and never closer than 2 km — never your street. To work out how far, we compare postcodes on our own server, using a table of German postcodes from GeoNames (CC BY 4.0); no map service is asked and nothing about you leaves our server. If we have no address of yours, you can give us just a postcode for books to pick up near you; we keep it with your account until you change it. The line you add for whoever picks up is shown with your books. Where you meet, you agree in the order's messages. The legal basis is the service you asked for (Art. 6(1)(b) GDPR).
Books you list. Title, author, condition, language, your note about the book, and any cover photo you take yourself. This is what other people browse.
Your shelves. The book categories you pick under “What do you like to read?”, and when you were asked. We use them only to put those shelves first on the home page for you. Nobody else sees them, and you can change them at any time. The legal basis is the service you asked for (Art. 6(1)(b) GDPR).
Where you came from. If you arrive through one of our short addresses, such as hoppingbooks.de/kita, and create an account in the same visit, we store the word in that address ("kita") with your account, to see which ways of telling people about HoppingBooks work. Arrivals through these addresses are counted per day as plain numbers, with no cookie and nothing about who you are. The legal basis is our legitimate interest in knowing which of our outreach works (Art. 6(1)(f) GDPR).
Ratings and reader notes. The stars you give a book and anything you write about it, and the stars and words you give the person who sent you a parcel. These are public and shown next to your name to anyone using the site. You can change or remove any of them, which removes them from the site.
Messages. Messages you send the other member on an order, and who sent them.
Claims and parcels. Which books were claimed, what postage and fee were charged, the status of the parcel, and — once posted — the tracking number and carrier. If the carrier later bills a surcharge because the parcel was bigger or heavier than its size, we record that against the parcel, so we can ask a donor whose parcels keep being bigger to check their sizes.
Payments. Payments are handled by Stripe. We never see or store your card number. What we keep is the identifiers Stripe gives us so we can match a payment to a claim.
Images you upload. Profile photos and cover photos are stored as files rather than in our database. For each upload we also record the time, the size and the storage key, so we can enforce a daily limit and remove images nothing refers to any more.
Technical data. Our host keeps server logs, which can include IP addresses, for security and troubleshooting. Before you commit to a book we also estimate postage using a country code our host derives from your IP address. We do not store that country code, and it tells us your country, not your location.
Account sign-ups. When an account is created we record the time and a one-way hash of the IP address it came from, so that accounts cannot be created endlessly from one place. The hash is salted with a secret we hold, cannot be turned back into an address, and the record is deleted after 24 hours. We keep it only for that check.
Two things here are decided by software rather than by a person, and both are about a listing rather than about you:
Neither one closes an account or takes money. Those are always decided by a person.
You can also report a member, at the foot of their profile. That report reaches only us: we keep who reported whom, the reason and anything you add, for as long as both accounts exist. The member is not told who reported them, and nothing happens to their account on its own.
| What for | Legal basis |
|---|---|
| Your account, claims, postage and payments | Performance of a contract — Art. 6(1)(b) |
| Keeping the service safe: sign-up and upload limits, reports, content checks | Legitimate interests — Art. 6(1)(f) |
| Records of completed transfers and payments | Legal obligation — Art. 6(1)(c) |
| What you choose to publish: photo, bio, ratings, reader notes | Consent — Art. 6(1)(a), withdrawn by removing it |
Where we rely on legitimate interests, the interest is keeping a small service usable and free of abuse, and we use the least we can: a hashed address rather than an address, a count rather than a history.
The person at the other end. This is the important one. To post you a book, the sender needs a label with your name and postal address on it, and they will see it. Equally, when you give a book away, the person receiving it sees the name on your profile. There is no way to post a parcel without this. Everything you publish — your name, photo, bio, books and ratings — is visible to anyone using the site, signed in or not.
Services that work on our behalf. Hosting, file storage and logs (Netlify); our database (Prisma Data Platform); payments (Stripe); postage labels and tracking (Sendcloud); the emails we send you (Resend); reading cover photos and sorting books into themes (Anthropic). Each of these acts on our instructions under a data processing agreement, and each sees only what it needs.
Book catalogues. To fill in a book's details we ask Google Books and Open Library about an ISBN, and the Deutsche Nationalbibliothek about a German one, and the covers on our shelves come from Open Library. Those requests are made by our server and contain the book's number only — never anything about you. A cover is copied once into our own storage and served from there, so your browser never calls a catalogue.
Searching beyond our shelves. When a search finds few or no books on HoppingBooks, we also ask Google Books and Open Library for books matching what you typed, so you can wish for one we don't have yet. The request is made by our server, so neither is given your IP address, and it carries nothing else about you: not your name, not your account. Results are shown without the catalogue's cover, so your browser never calls them. If you wish for one, we store its title and author with your wish, as for any wish. The legal basis is our legitimate interest in a search that does not end where our shelves do (Art. 6(1)(f) GDPR).
Reading a cover photo. If no catalogue knows a book's barcode, you can photograph its cover so we can find the book. The photo is sent to Anthropic, whose model Claude reads the title and author from it, and we search the catalogues with those words. Only the photo of the cover is sent — nothing about you — and Anthropic's commercial terms do not let it train its models on what we send. The photo becomes the book's cover on our site, like any cover photo you take. The legal basis is the performance of our contract with you (Art. 6(1)(b) GDPR).
Sorting books into themes. To show a shelf's books by theme, such as “If you like horses”, we send Anthropic a book's title, author and description, and its model Claude picks the themes. Only the book is sent — nothing about you. The legal basis is our legitimate interest in shelves that are easy to browse (Art. 6(1)(f) GDPR).
Address suggestions. When you type a delivery address, we ask Google's Places service to suggest matching addresses, so that a parcel is not lost to a typo. What you type in that field is sent to Google — including a partial address as you type it — along with the countries we deliver to. The request is made by our server, so Google is not given your IP address, and it carries nothing else about you: not your name, not your account, not what you are claiming. Suggestions are a convenience, not a requirement: type the address in full and ignore the list, and nothing is sent to Google.
Some of the services above are operated by companies based in the United States and may process data outside the European Economic Area. Netlify, Prisma, Resend, Anthropic and Google are companies in the United States. Transfers there rest on the EU–US Data Privacy Framework (the European Commission's adequacy decision of 10 July 2023) where the company is certified under it, and otherwise on the Commission's standard contractual clauses. Stripe handles payments for us through its European company in Ireland, and Sendcloud is based in the Netherlands.
Your account and what is attached to it are kept while you have an account. Specifically:
| What | Kept for |
|---|---|
| Hash of the address an account was created from | 24 hours |
| Sign-in links | 15 minutes, and once used they stop working |
| Records of images you uploaded | 30 days |
| Photos nothing refers to any more | Removed by a weekly sweep |
| Your account, listings, ratings and messages | While the account exists |
| Records of a completed transfer and its payment | As long as German tax and commercial law require, up to ten years (§ 147 AO, § 257 HGB) |
Server logs are kept by our host for a short period and then discarded.
No service can promise it will never be breached. If one happens and it puts you at risk, we will tell you and the supervisory authority, as the law requires.
You can ask us, at any time and free of charge, to:
You can delete your account yourself: at the bottom of your profile, under Delete account. We email you a link to confirm it, which works for an hour while you are signed in. Your account, your books, ratings, wishes, messages, saved books and addresses are then deleted, and we email you to say so. Past orders are kept without your name, because we have to keep the record of a transfer and its payment. We also note, without your name or email, when you joined and left, how you signed up and where you came from, and how many books you listed, gave and received, so we can see why people leave. While an order of yours is still under way, it has to finish first. You can also write to the address above and we will do it for you.
If you think we have handled your data badly you can complain to a supervisory authority — the one where you live, where you work, or where the thing you are complaining about happened. Ours is the Unabhängiges Landeszentrum für Datenschutz Schleswig-Holstein (ULD), Holstenstraße 98, 24103 Kiel, datenschutzzentrum.de.
We set five cookies, and all five are strictly necessary: one that keeps you signed in, one that protects sign-in forms against cross-site request forgery, one that remembers you have seen the welcome screen, and one that remembers someone has been signed in on this browser, so that next time you are shown the sign-in form rather than the one for creating an account, and, only if you choose a language on your profile, one that remembers that choice. The last two hold no name, email address or other detail about you. If you sign in with Google, two more are set for the trip to Google and back, to check that the answer belongs to your request; they last at most 15 minutes. There are no analytics or advertising cookies.
Two more things are kept in your browser’s own storage rather than sent to us: the parcel you are putting together while you browse, so it survives a reload — the same thing a shopping basket does — and, if a page ever fails, a short log of what the app was doing, which stays on your device and helps you tell us what went wrong.
All of it is needed for a service you asked for, so under § 25(2) TDDDG none of it requires your consent. That is why this site has no cookie banner: we would only be asking you to agree to what we cannot work without. Clearing your browser data removes all of it.
HoppingBooks is not intended for children. You need to be at least 16 to have an account, or the age of consent for data processing where you live if that is lower.
When you tap “I want this book” on a book that is not available, we store the book's title, author, language and cover against your account, with the date. We use it to email you when someone lists a copy, and we count wishes to show which books are wanted. That public list shows only how many people want a book, never who. A wish stops counting after about six months unless you renew it, and you can remove it from your profile at any time. The legal basis is the service you asked for (Art. 6(1)(b) GDPR).
The box for it is ticked when you sign up, and you can untick it; you can also switch it on later in your profile. Either way we first send you one email with a link, and only if you press it do we email you once a week, on Fridays, with books newly listed on HoppingBooks and books people are looking for, and now and then a video about reading that we pick (double opt-in). A video is a link to YouTube: the email loads nothing from YouTube, and only if you open the link does YouTube see your visit. That press is your consent. The box is separate from accepting the terms, and an account never depends on it. We store when we asked and when you confirmed, as proof of your consent (Art. 6(1)(a) GDPR, § 7(2) UWG). You can withdraw it at any time in your profile or through the link in every such email, which ends them from then on.
One more email, without that box: if you sign up and, three days later, have not yet listed, requested or wished for a book, we send you one email with tips for getting started, as the sign-up page says. It goes once, never again, and only to accounts created with the form since 2 October 2026, or in any other way (with Google, or an email link) since 8 October 2026. The legal basis is our legitimate interest in helping new members get going with the service they signed up for (Art. 6(1)(f) GDPR, § 7(3) UWG).
Once you have ordered a book, we may also now and then email you tips about HoppingBooks itself, as checkout says (§ 7(3) UWG, Art. 6(1)(f) GDPR). You can object to these tips, and to the one after signing up, at any time and at no cost: with the link at the bottom of every such email, in your profile under Tips by email, or by writing to us. We note when you did, and send you none from then on. Emails about your orders and your account are not affected.
Emails about what you do on HoppingBooks — a book you requested, a book you asked to be told about arriving, resetting your password — are part of the service and do not depend on this consent. A message that a book you asked for has arrived is about that book only. The weekly email is sent through Resend, like every email we send (see “Services that work on our behalf” above).
If what we do with data changes, this page changes with it, and the date at the top is updated. If the change is significant we will tell account holders directly.