Library Software
Catalog your book library
Automatically download book details and imagesLike author, title, publisher, genres, subjects & cover art.
Just search our huge online book database ... ... by ISBN or by author & title.
Over 40 million ISBNs recognizedGuaranteed 97% success rate on your ISBN searches!
CLZ Books
Mobile
Mobile app for your phone or tablet
iOS & Android
iOS & Android
USD $19.95
per year
More about the mobile app
CLZ Books
Web
Web-based software for your computer
Windows & macOS
Windows & macOS
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
New setting to disable book values
Jan 09, 2026
v10.5 iOS: Disable book values / Search by ISBN10
Jan 07, 2026
v10.5 Android: Smoother navigation / Disable book values / Search by ISBN10
Jan 06, 2026
New: track your Reading History, plus other new data fields
Dec 17, 2025
v10.4: “One-by-One” mode for adding books by ISBN
Nov 14, 2025
Jan 16, 2026
Worth the cost!
I don’t usually do app reviews but I’m compelled to do one for CLZ Books given my experience over the past year and specifically within the past couple days.
I’ve been using CLZ Books for a few years now, to varying degrees, but I have really started to put it through some hoops in the past year as I’ve finally begun to organize and catalogue my book collection, now approaching 2250 titles.
I first got it to replace another library app that went defunct, to help me avoid my common mistake of buying a book I already had, but I was quickly a fan of how easy it was to add books to my collection and to make notes for each entry. And with every update, improvements were made that made organizing my library a little bit easier.
There is a lot of data available for almost any book you might have, and adding books not in their database is pretty easy.
The best part of CLZ Books is the responsiveness of their customer support. The other day I had to reinstall CLZ Books on a new phone, and after I’d synced my library to the cloud, the app kept crashing. I was despondent because organizing my library has been a big part of my daily life for months, and the thought of not being able to use the app as a resource was rough.
I looked through the online CLZ community for any hint as to what was going on, and I fired off an email to CLZ support describing my situation. Within hours, I received a reply that a bug had been detected in a recent update and that they’d just pushed through a new update to resolve the issue. Sure enough, once I downloaded and installed the new update, it worked perfectly and I can now continue to organize my library.
Is it perfect? No, there are some sorting and search issues that can be improved upon, but I’m relatively confident that CLZ support will be responsive to comments and questions on the various forums and emails and get us to as close to perfect as we can expect.
I first got it to replace another library app that went defunct, to help me avoid my common mistake of buying a book I already had, but I was quickly a fan of how easy it was to add books to my collection and to make notes for each entry. And with every update, improvements were made that made organizing my library a little bit easier.
There is a lot of data available for almost any book you might have, and adding books not in their database is pretty easy.
The best part of CLZ Books is the responsiveness of their customer support. The other day I had to reinstall CLZ Books on a new phone, and after I’d synced my library to the cloud, the app kept crashing. I was despondent because organizing my library has been a big part of my daily life for months, and the thought of not being able to use the app as a resource was rough.
I looked through the online CLZ community for any hint as to what was going on, and I fired off an email to CLZ support describing my situation. Within hours, I received a reply that a bug had been detected in a recent update and that they’d just pushed through a new update to resolve the issue. Sure enough, once I downloaded and installed the new update, it worked perfectly and I can now continue to organize my library.
Is it perfect? No, there are some sorting and search issues that can be improved upon, but I’m relatively confident that CLZ support will be responsive to comments and questions on the various forums and emails and get us to as close to perfect as we can expect.
Reviews from customers
Jan 16, 2026
Excellent and usable app
I got convince by a Martha Stewart review a long time ago, and this has been extremely useful. The step to making it even more useful is to take the physical books and sort them by the Library of Congress number which is in the database.
Jan 7, 2026
So useful!
This app provides a great way to catalog your library. Intuitive and easy to use, and constantly being improved by the developers. Love it!!!
Dec 22, 2025
The best one
tried a lot of different library apps and this is by far the best one. they have most of the special editions I own, even brand new ones that aren't on the market yet and if they don't have it, it's easy to add, while I really struggled with finding and adding special editions on other apps. also love that it's independent owned and run by a small team!!
Dec 11, 2025
The best
This is the 3rd library app I've sampled and far and away the best! It scans the isbn number even if there's no barcode. It easily identifies the isbn inside a paragraph of words. This makes the job go so much more smoothly!
Oct 27, 2025
EZ to Use
Really well done app. Very intuitive. Was able to catalog over 300 books in fairly short order. Cloud sync with export capabilities. I would like to see the export categories be selectable in future update releases - that would be a bonus! Recommend to all - young children could help sort the library with this - it is that EZ.
Oct 23, 2025
Awesome
This is an amazing app for tracking a library or adding books. I have a library of 2000 books and it transferred very easily...and I am not too good at that stuff. However, the app has been wonderful for not only me, but my family uses it as well. I had my library uploaded to it in about 25 mins and cleaned up quite a bit. I highly recommend this app. It is very functional!
Oct 8, 2025
Forever Lover of CLZ
I have been using CLZ since what seems like infancy days when I had to organize a very very large library of a film director/historian. I have seen CLZ grow like GREAT technology and it’s worth every penny I pay in my low budget to organize the great books
Thank you CLZ programmers and investors. We need more of both of YOU!!
Thank you CLZ programmers and investors. We need more of both of YOU!!
Sep 26, 2025
NC HB 805 life saver for our school!
NC passed law HB805 that requires schools to post searchable catalogs of library books online and allows parents to block their children from borrowing certain titles, beginning with the 2025-26 school year. This app made the process easy & we were able to log over 25,000 books in 4 days thanks to it & wonderful PTA volunteers!
The app is not perfect but it is economical & easy to use. It saved us TONS of time compared to the protocol that the county suggested we use. HIGHLY recommend if you’ve got lots of books to catalog!
The app is not perfect but it is economical & easy to use. It saved us TONS of time compared to the protocol that the county suggested we use. HIGHLY recommend if you’ve got lots of books to catalog!
Sep 7, 2025
Excellent catalog
A very good tool for tracking books. Allows a lot of details to be included, if you care. (For instance, the original title and the translator of a book originally published in another language; or the location of a book in your library.)
Books can be catalogued either by ISBN or by title and author. The ISBN lookup is quite good, and easy to correct or extend.
My wife and I have used it for years, for our 7000-odd book collection, and it’s been a great experience. The developers are also open to suggestions.
Books can be catalogued either by ISBN or by title and author. The ISBN lookup is quite good, and easy to correct or extend.
My wife and I have used it for years, for our 7000-odd book collection, and it’s been a great experience. The developers are also open to suggestions.
Aug 16, 2025
VERY capable app
This app is so feature filled it is just amazing. My husband has a library of 5,000 books we thought we would never catalog and now I have got have of them in my CLZ database already. I have a few minor issues and suggestions which I am going to send to the developer separately, but in general, I love this app.
Jul 26, 2025
Wonderful tool
Just a note to say thanks very much for your wonderful tool. I was able to use it to easily and quickly catalog my mother's collection of scholarly scandinavian books. The cloud feature is wonderful, as I am now able to share the library with universities who are interesed in receiving the books. I had originally planned to use a spreadsheet and photos, uploading it to dropbox, but this is so much better.
Thank you so very much.
Thank you so very much.
Jul 21, 2025
So easy to use!
I helping a friend move & she is reducing her considerable library for the first time in 20 years. Over 500 books scanned by CLZ and easily tagged for keep, resell, & donation. So easy to use! The CLZ app makes all of that possible. I like the desktop version for modifying or editing any folders or books but quick fixes.
Jun 20, 2025
This app is a game changer!
I was assigned the task of cataloging my father’s library, a retired professor with over 3000 books. I have tried to use other apps and struggled. This app is a game changer and a life saver! It’s so easy to scan multiple items and finds titles quickly, it syncs with my computer, and I was able to create a print out to show my father the list with Book cover images! There is no other app like this one! Thank you for creating this!
May 31, 2025
Great investment
This app is a great investment. Keeps my library cataloged beautifuly.
May 24, 2025
Easy to use
Easy to use- my library is now catalogued!
Apr 14, 2025
Easy to use
Just what I needed. Easy to use. Scan the code and add it to your library.
Mar 18, 2025
Excellent app
I had used Delicious Library back in the day but this blows that completely away. The functionality is great and the appearance is uncluttered but complete. Very easy to use and responsive developers!
Mar 5, 2025
Essential
This is such an essential app for anyone with an extensive library or for those who like to keep their collection organized and accessible. Also a great tool to keep a record of the books you own in the event of a worst case scenario. Easy to use and extensive with a lot of features. Love it!
Feb 26, 2025
Absolutely amazing!
Everything I wanted and needed to catalog my library!
Feb 24, 2025
Astonishingly good
CLZ Books is the most wonderful piece of software, enabling me to keep track of my library. Loading new books is made easy through use of ISBN recognition, and the editing and display options are easy to operate and comprehensive. The owners and software engineers must be congratulated on producing a really astonishingly good product.
Dec 4, 2024
CLZ books library
I’ve been with Book Collectors Connect, now CLZ, for many years. Best way to keep a large library of books. I appreciate the ease of use program and the team is readily available whenever you have questions or need help.
Nov 24, 2024
Lifesaving!
Cataloging my over 1000 book Time Life Library...Lifesaving!.. I've cataloged my Time Life record collection on CLZ as well!
Nov 23, 2024
Excellent app!
My partner and I have been using CLZ Books to organize our 1,000 plus library since the beginning of November. The upgrade with ISBN character recognition gave us an huge boost just as we were beginning to bog down. The whole app is just wonderfully done. We sent a question to support one evening and had the clear answer the next morning.
Nov 22, 2024
Phenomenal
This app has been phenomenal for me over the last year (& some change)! It was recommended to me by someone who I chatted about books with a lot, after being mentioned in passing as a way she kept her own library (& urge to organize) in check. When I had a big move coming up, I asked her to remind me the details, and if she thought it was worth the subscription costs, and she enthusiastically did so. Despite the recent increase in annual cost, this epic tool has been a life (& wallet) saver!
Nov 22, 2024
The best I’ve found
I have over 1200 books and have used a number of catalog apps over the years. CLZ Books does the job of keeping track of my library and gets syncing right. Most importantly (speaking as a software developer) they keep improving the app. It’s tough to make a business of niche software products. These folks have apparently figured out how to make a go of it and they keep improving. Kudos to them!
Nov 16, 2024
An excellent app
I have used this app for over a decade and it just continues to get better and better. I highly recommend it if you have a library of books to keep track of.
Nov 15, 2024
User-friendly for all age groups
Finding this app at 63 was a blessing. I have an extraordinary library and continue to collect, yet sometimes you find out you already have the book. This app has been helping me keep track of my existing library and when shopping, I pre-scan the book to ensure I don't own it. Thank you.
Nov 8, 2024
Lifesaver
I would just like to thank you for your marvelous Book Collector application. It has been a mainstay that helps me manage my book library for many years now. The flexibility is incredible and accomodates my changes in the way I access and use my books. I am about to finish my MA degree and during my school years I used this application to quickly find books on topics I was doing research papers about. It has been a lifesaver!
Blessings on you for creating and maintaining this application.
Blessings on you for creating and maintaining this application.
Nov 6, 2024
Useful tool
My wife is the library committee chair for our retirement community and we have used CLZ Books as our catalog for our 1600 books. it gives us many useful tools for this activity. We know what we have in our collections so we can check donations for duplicates. We use it when we order or shop for books to ensure that we don't purchase duplicates and waste our limited funds. The fact that we can see our cloud library on all of our devices makes this available anywhere and for both of us.
Aug 21, 2024
The best I have found
I have over 1200 books and have used a number of catalog apps over the years. CLZ Books does the job of keeping track of my library and gets syncing right. Most importantly (speaking as a software developer) they keep improving the app. It’s tough to make a business of niche software products. These folks have apparently figured out how to make a go of it and they keep improving. Kudos to them!