Book Database Software

Catalog your book collection

Keep track of your book collection and wish listUse the mobile app or the web-based software (or both!)
Automatic book details and cover imagesJust search our huge online book database by ISBN
Over 40 million ISBNs recognizedGuaranteed 97% success rate on your ISBN searches!
CLZ Books icon CLZ Books
Mobile
Mobile app for your phone or tablet
iOS & Android
example
USD $19.95 per year
More about the mobile app
CLZ Books icon CLZ Books
Web
Web-based software for your computer
Windows & macOS
example
USD $39.95 per year
More about the web app
CLZ Books
Mobile + Web
CLZ Books Mobile
1 year
+
CLZ Books Web
1 year
USD $0.00
USD $0.00
save USD $0.00

Or... use them both,
as perfect companions!

Both CLZ Books Mobile and CLZ Books Web can be used on their own, as a stand-alone solution. But these tools really come to life when used together, as they are great companions. While away from your computer use CLZ Books Mobile on your phone, then use CLZ Books Web at home, to work on your database on a big screen, with a real keyboard. Of course, you can sync your database between them through our CLZ Cloud solution.

Latest software updates

Apr 1, 2026
Simply the Best!
This is my third book cataloguing app over the last 20 years, and it is hands down the best. Basically does everything you would want, but most importantly it is actively supported by a clearly dedicated team of developers. My previous apps all eventually withered because the developer(s) lost interest. CLZ seems to be an actively maintained app with frequent updates (the true test).
Highly recommended.
LEK2 (USA) on CLZ Books Mobile

Reviews from customers

Apr 20, 2026
What a great app
I’m in my senior years which means 2 things.
1. I have collected a lot of books through the years.
And 2. I’m not as sharp as I used to be.
This app sorted out my library extremely well , efficiently and graphically smart. Love it.
And 3. The folks at CLZ.provided excellent support to sort out my age addled brain, for which I thank them very much. Both product and support are well deserving of my ranking.
Excellent.
Barton (United Kingdom) on CLZ Books Mobile
Apr 19, 2026
Beste Bücher-Datenbank, bester Support - einfach perfekt!
Ich habe die CLZ-Datenbank vor vielen Jahren von meinem Mann geschenkt bekommen, nachdem ich mir ein Buch doppelt gekauft hatte – und war von Anfang an begeistert.
Seitdem organisiere ich wirklich alles darin: Reiseführer, Kochbücher, Hörbücher und sogar Straßenkarten. Besonders toll finde ich die vielen Felder, die sich ganz flexibel an die eigenen Bedürfnisse anpassen lassen.
Auch die Newsletter sind sehr verständlich geschrieben, Neuerungen werden klar erklärt. Man merkt einfach, dass hier viel Herzblut drinsteckt. Und falls doch einmal eine Frage offen bleibt, ist der Support unschlagbar gut.
Ich wüsste ehrlich gesagt nicht mehr, was ich ohne CLZ machen sollte – von mir gäbe es am liebsten 10 Sterne!
chicken_66 (Germany) on CLZ Books Mobile
Apr 18, 2026
Extremely easy to use
So far it has extremely easy to use, despite the majority of my collection needing to be added manually.
BJ Reeve on CLZ Books Mobile
Apr 15, 2026
Perfect for managing my books
It's been perfect for managing my books, the only problem I have is finding the time to scan all of them. I had a weird issue with data being cached, but support were excellent and it's all sorted within about 3 hours.
Andrew Wynn on CLZ Books Mobile
Apr 14, 2026
Very nice app
I have been using it for years. With pleasure. This app and desktop application are very well synced.Highly rwcommended.
nepoznata osoba on CLZ Books Mobile
Apr 14, 2026
Exactly
Awesome app I have scanned all my books and it’s so much easier to see what books I have.
Nana774 (USA) on CLZ Books Mobile
Apr 14, 2026
Nice app
It's a really nice app, i tried many in the past for catalog my books, i choosed that, I'm happy from many years now.
Nicolas Francfort on CLZ Books Mobile
Apr 14, 2026
Library on tap
This app is so easy to use and maintain and provides me with exactly the information, index and library of my books. Great app.
Duke Nukes (United Kingdom) on CLZ Books Mobile
Apr 14, 2026
Truly a life saver
Everything is going great. The ease of use is astonishing! All of my books, so far, have scanned in with no problem. It is truly a life saver for anyone wanting to catalog their book collection.
Chandra on CLZ Books Mobile
Apr 14, 2026
wouldn't change it ever
been using this for years. can store in cloud in case phone malfunctioning. currently have around 1000 books.
Bob Kelley on CLZ Books Mobile
Apr 12, 2026
Easy to use tool
Just such an easy to use tool to make a virtual catalogue of your library.
Nathan Vandenberg on CLZ Books Mobile
Apr 7, 2026
Support Team very efficient
I initially purchased the Book Collectorz desktop software over 12 years ago. Since then my collection has grown to more than 1600 books. With the CLZ Books App I can have this wealth of information with me all the time. I find this App excellent value for the money paid and the Support Team very efficient whenever I had a question.
Gabriele Angst on CLZ Books Mobile
Apr 7, 2026
Very extensive cataloging system
I've used this app for a number of years; it has grown into a very extensive cataloging system, with easily searchable databases. my library includes hardcover, paperback, softcover books along with bound paper groups. I have several major topics- with Alwin's input, I've been able to sort the master list into various topics using "tags". The needed information was in the online manual, but I needed Alwin's help to figure my way thru. very patiently providing online help.
John Brackett on CLZ Books Mobile
Apr 6, 2026
Great app!
Outstanding app. Scans isbn numbers with your camera and finds extremely obscure books!
Kavod222 (Italy) on CLZ Books Mobile
Apr 4, 2026
Top Notch
Bloody marvellous, well done sirs.
BlackDog123 (United Kingdom) on CLZ Books Mobile
Apr 2, 2026
Terrific!
Now up to 2800 books and counting - a great bit of software backed up by readily accessible support. Congratulations.
Rudall Carte (United Kingdom) on CLZ Books Mobile
Apr 1, 2026
Book Library
Makes keeping track of all reading so easy.
Celest Rattliffe (USA) on CLZ Books Mobile
Apr 1, 2026
Simply the Best!
This is my third book cataloguing app over the last 20 years, and it is hands down the best. Basically does everything you would want, but most importantly it is actively supported by a clearly dedicated team of developers. My previous apps all eventually withered because the developer(s) lost interest. CLZ seems to be an actively maintained app with frequent updates (the true test).
Highly recommended.
LEK2 (USA) on CLZ Books Mobile
Mar 29, 2026
Best user friendly database for books
I have been using this app for many years and have not been disappointed. This app is constantly upgrading to make it easier to use with less work on my part and It is reasonably priced. I highly recommend this app.
maine fanclub (USA) on CLZ Books Mobile
Mar 26, 2026
The Library Organizer
I’ve been using this handy app for many years to keep track of my books that I’ve read and want to read. It has prevented me from buying a book that I’ve already read or have on my bookshelf (either a physical book or on my Kindle).
The developers are responsive to problems and suggestions for improvement. Bottom line: an invaluable resource for library management.
Daniel always Reading (USA)
Mar 25, 2026
Excellent app has made cataloguing a 2500 book library a breeze.
on CLZ Books Mobile
Mar 24, 2026
Best app for book collectors
I’ve used the CLZ Books app for over 5 years. Before this, my books were everywhere and I had a hard time finding them. I had a system using photos in my phone, but it was not very effective. CLZ allowed me to categorised the books by location, and was easy to upload using ISIN barcodes that could be scanned. Each time a book got identified, it included a wealth of information about the book and publication. Anyone who has over 100 books in their possession ought to use this app. Best thing is: they keep improving their offering.
Mmmjjj145 (USA) on CLZ Books Mobile
Mar 24, 2026
A Library’s best friend
I’ve been using CLZ for a while now and am slowly organizing my library with it’s help. Easy to use and allows me to put all the information from my library, both physical and digital into one place. Highly recommend.
Well planned app (USA) on CLZ Books Mobile
Mar 24, 2026
Excellente application
Excellente application, pour 1€/mois, sans publicité, vraiment bien conçue. Ajout des livres (code- barres). Permet d’enregistrer facilement chaque livre (titre, auteur...) et d’organiser sa bibliothèque de façon claire et efficace. La prise en main demande un léger temps d’adaptation, mais l’utilisation devient ensuite très fluide. Utile quand on possède beaucoup d’ouvrages : on évite les doublons, on sait immédiatement ce que l’on a, et l'on choisit plus facilement sa prochaine lecture.
Michel BLAISE on CLZ Books Mobile
Mar 24, 2026
Keep track of all your books
I love this app. I use the comic collecting version as well. It keeps all your books in one place and is highly customisable. For instance I have a custom field which helps me keep track of what I’ve read, notes for what I thought about it and it just works flawlessly.
A great app for any bookworms out there!
AndyY1508 (United Kingdom) on CLZ Books Mobile
Mar 24, 2026
Absolutely love this whole app
I absolutely love this app and every other part that goes along with it. The price is amazing and the customer service is second to none. Never any problem whatsoever and it’s a pity I can only leave 5 stars because I would leave more if possible. A literal life changer if you are a book lover like me who likes to be super organised.
Maryann Conway (United Kingdom) on CLZ Books Mobile
Mar 24, 2026
This app is very easy to use. Love it!
I use mainly to record titles I have read and those I wish to read or avoid. it includes basic bibliographical information as well as the option to add extras and notes. I wouldn't be without it.
Mary Ross on CLZ Books Mobile
Mar 24, 2026
Highly recommend it
couldn't live without it! it helps me keep track of all my books, which helps so I dont buy duplicates. it also picks random books if you shake it, which helps with my indecision. I especially love all the stats it gives you. I love that I can put my reviews and stars in it, too, not just on goodreads. I have had this for years now, and it's worth every penny.
The Sunshine Breakthrough on CLZ Books Mobile
Mar 24, 2026
App very helpful when buying books
This app has saved a fortune by allowing me to check whether I have already bought it already.
Bracknell (United Kingdom) on CLZ Books Mobile
Mar 24, 2026
20+ Years of Reliable Service – Still the Best Book Cataloging App for Serious Collectors
I’ve been using CLZ Books (and its earlier desktop predecessors) for over twenty years, and it remains the gold standard for managing a serious home library. My collection now sits at nearly 4,000 volumes, almost entirely hardcovers, spread across multiple bookcases. CLZ has helped me keep everything meticulously organized—by author, genre, location, condition, purchase details, and more—without ever feeling overwhelmed.
The real game-changer has always been the mobile apps (iOS and Android). When I’m browsing in a bookstore or used bookshop, I can pull out my phone, scan the ISBN with the built-in camera scanner (which has an impressively high success rate), and instantly see whether I already own the title. No more accidental duplicates! That simple feature has saved me money and shelf space countless times over the decades.
What I appreciate most about the CLZ team is their ongoing commitment to improvement. They don’t just maintain the software—they actively listen to users and keep adding thoughtful features. The latest major update introduced individual Reading History tracking, which allows multiple read sessions per book with fields for Start/End Dates, Reading Status, Progress, and—best of all—a dedicated Reader field. My wife and I can now each log our own reading experiences on the same book entry (perfect for books we’ve both enjoyed at different times). Previously I relied on custom tags for this, which worked but felt clunky. The new system is far cleaner, more flexible, and syncs beautifully between the mobile apps and the web/desktop versions.
Beyond reading tracking, the app lets me customize almost everything: personal notes, ratings, locations in the house, purchase price and store, condition, and even custom fields for whatever unique details matter to me. Automatic cover art and core data (author, publisher, plot summary, genres, subjects) pull in reliably from their database, yet I can override anything if needed. Cloud sync keeps my entire collection backed up and accessible across devices, so I can update on my phone while traveling and refine everything on the big screen at home.
For anyone with a growing or already large collection—especially if you value accuracy, portability, and long-term reliability—CLZ Books is worth every penny of the subscription. The developers clearly care about bibliophiles like us, and after two decades, I’m still impressed by how much better it gets with each update. Highly recommended—whether you’re just starting to catalog or, like me, have been at it for years.
Rating: 5/5 Stars
Mikil H (USA) on CLZ Books Mobile