Keep track of your book collection
Just scan your ISBN barcodes
Automatically download book details by ISBNLike 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!
Mobile
Mobile app for your phone or tablet
iOS & Android
iOS & Android

USD $19.95
per year
More about the mobile app
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
Sep 1, 2025
My book catalog story
I love my CLZ book catalog. I had always wanted to catalog my books and back in the days of card catalogs when I was young, I made an index card file (which I still have). I had far fewer books then. Now I have about 3,000, with book cases in almost every room of our house, and it is hard to keep track of them all in my head. So, one of the practical reasons for having a catalog is to record the location of each book by room and bookcase and in some cases even by shelf. I just have to remember, if I move a book, to change the location in the location field of my catalog. I have been able to locate books with my catalog instead of wasting time searching from room to room.
I have the mobile version as well, for several reasons. Sometimes when I’m in a bookstore, I am not sure whether I already bought a certain book or not; I can tell it is a title I would have liked to own, but I can’t remember if I actually bought it. At least twice I bought a book I already had. Now I can check my mobile catalog. When I finish reading a book, it is quicker to enter that on the “read” field on my phone than to remember to record it next time I am on my catalog on the computer. I can also stand in front of a bookcase with my phone and check whether all the books are cataloged and whether the location is correct.
Beyond practical reasons, I just love having my books organized and cataloged for mental clarity and the pleasure of looking at the titles and covers on the screen. I had once thought of making my own database of my book collection, but it wouldn’t have been nearly as sophisticated as the CLZ one and wouldn’t have included photos of the book covers. Some of my large categories, such as art books, children's books, and Christmas books, have beautiful colorful covers which are a pleasure to look through on the CLZ catalog. I used the genre field to make up my own categories, many of which are not actually genres but the subjects that are important to me. I love that the CLZ software keeps track of the numbers in each category, so for example I know that at the moment I have 184 art and design books, 248 architecture and interiors, 169 autobiography/memoirs, 102 tea books, 213 on England, 206 on New England, 235 children’s books, and 175 Christmas. It’s just interesting to me to know this. It’s a picture of my interests.
So far I have cataloged 2300 of my books. I really enjoy working on the catalog, but it takes time and not all of my books are easily accessible. My method is to scan my new books right away with the app on my phone that CLZ provides, then add them into the collection when I have time to sit at the computer. Then I go to the backlog of older books as I have time and add them in. Some of the oldest ones pre-date the ISBN system and take longer to enter manually. I realize it will take a long time until I am completely caught up, but it’s a goal I’m working towards. I have barely begun to catalog the e-books on my Kindle as that is not as high a priority but will eventually include them as well.
I’ve loved books all my life and also enjoy organizing (probably should have been a librarian), so making a catalog with the CLZ software is a great fit for me.
In the years I’ve been involved with the CLZ catalog, the software has consistently and vastly improved. Many of my books are rather obscure, but more and more of them are recognized in the enormous CLZ database and come in with many of the fields populated and with the cover photo. Previously I had to take my own photos of some of the book covers and upload them, and those photos don’t come out perfectly, but now most of the books come in with the cover when I enter the ISBN or can be found on the “search the internet” feature. More and more information about the books is now included, so that my catalog is an amazing resource.
The CLZ company is extremely responsive when I have contacted them with a question. I don’t know how large or small the company is, but I get a personal response to my emails. I feel confident that they will help me with any catalog questions, and I have a very positive view of the company.
I recommend CLZ Books Web and Mobile to anyone who wants to make a beautiful and useful book catalog. You will be able to sit and scroll through your library and remember books you might not have focused on for some time. You will be able to enjoy looking at the covers of the precious books you have collected and be happy you have them. You will feel organized and be able to locate books in your home. You will have fun with your catalog if you’re anything like me! I even told our local branch librarian about CLZ for his own book collection.
I have the mobile version as well, for several reasons. Sometimes when I’m in a bookstore, I am not sure whether I already bought a certain book or not; I can tell it is a title I would have liked to own, but I can’t remember if I actually bought it. At least twice I bought a book I already had. Now I can check my mobile catalog. When I finish reading a book, it is quicker to enter that on the “read” field on my phone than to remember to record it next time I am on my catalog on the computer. I can also stand in front of a bookcase with my phone and check whether all the books are cataloged and whether the location is correct.
Beyond practical reasons, I just love having my books organized and cataloged for mental clarity and the pleasure of looking at the titles and covers on the screen. I had once thought of making my own database of my book collection, but it wouldn’t have been nearly as sophisticated as the CLZ one and wouldn’t have included photos of the book covers. Some of my large categories, such as art books, children's books, and Christmas books, have beautiful colorful covers which are a pleasure to look through on the CLZ catalog. I used the genre field to make up my own categories, many of which are not actually genres but the subjects that are important to me. I love that the CLZ software keeps track of the numbers in each category, so for example I know that at the moment I have 184 art and design books, 248 architecture and interiors, 169 autobiography/memoirs, 102 tea books, 213 on England, 206 on New England, 235 children’s books, and 175 Christmas. It’s just interesting to me to know this. It’s a picture of my interests.
So far I have cataloged 2300 of my books. I really enjoy working on the catalog, but it takes time and not all of my books are easily accessible. My method is to scan my new books right away with the app on my phone that CLZ provides, then add them into the collection when I have time to sit at the computer. Then I go to the backlog of older books as I have time and add them in. Some of the oldest ones pre-date the ISBN system and take longer to enter manually. I realize it will take a long time until I am completely caught up, but it’s a goal I’m working towards. I have barely begun to catalog the e-books on my Kindle as that is not as high a priority but will eventually include them as well.
I’ve loved books all my life and also enjoy organizing (probably should have been a librarian), so making a catalog with the CLZ software is a great fit for me.
In the years I’ve been involved with the CLZ catalog, the software has consistently and vastly improved. Many of my books are rather obscure, but more and more of them are recognized in the enormous CLZ database and come in with many of the fields populated and with the cover photo. Previously I had to take my own photos of some of the book covers and upload them, and those photos don’t come out perfectly, but now most of the books come in with the cover when I enter the ISBN or can be found on the “search the internet” feature. More and more information about the books is now included, so that my catalog is an amazing resource.
The CLZ company is extremely responsive when I have contacted them with a question. I don’t know how large or small the company is, but I get a personal response to my emails. I feel confident that they will help me with any catalog questions, and I have a very positive view of the company.
I recommend CLZ Books Web and Mobile to anyone who wants to make a beautiful and useful book catalog. You will be able to sit and scroll through your library and remember books you might not have focused on for some time. You will be able to enjoy looking at the covers of the precious books you have collected and be happy you have them. You will feel organized and be able to locate books in your home. You will have fun with your catalog if you’re anything like me! I even told our local branch librarian about CLZ for his own book collection.
Reviews from customers
Aug 17, 2025
Great database
Great way to keep track of my books!
Jul 28, 2025
Keep track of all my books
I have used the CLZ comics and movies app and needed the book app to, to keep track of all my books. I have had no issues with any of the apps. They run smoothly and keep inventory of everything!
Jul 18, 2025
Perfect Library Organizer
For those like me who are obsessed with books (children’s books in my case), and have a copious amount, this is perfect for keeping track of what I have so I can stop buying doubles!
Jun 25, 2025
Absolutely love this app
Allows me to keep track of my books, which ones I have read, how I rated them, which location in the house I can find it. The team have made some great improvements such as reading the ISBN number when there is no barcode. Well worth the yearly subscription.
Jun 23, 2025
I love this app!
This has helped me keep track of my books and not by doubles it is the best app in the world.
May 22, 2025
Works great
This will help me keep track of my library at home and keep me from double buying books. :)
Apr 17, 2025
Love it!
Quick and easy. I use this app to keep track of all my role playing books.
Mar 5, 2025
Awesome
great way to keep track of the books you own! It is even backed up to the cloud! Awesome!
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.
Feb 9, 2025
No more duplicates
Easy way to keep track of what I own. It's saved me so much money from buying duplicates.
Jan 2, 2025
Huge range of functionality
Easy and fun to do. A great tool to keep track of you book collection.
Dec 31, 2024
Love this app
The best way to keep track of all my books. I absolutely love this app.
Nov 28, 2024
Great App
I use it all the time to keep track of my books. Definitely recommend it.
Nov 27, 2024
Absolutely Love
This app is exactly what I was looking for to catalog my books. I found myself buying duplicates, and decided to go in search of an app that would help me keep track of my books. CLZ Books - library organizer does exactly that and more. I keep books in different rooms in my house, I can note where the books are, mark if I have loaned them out and to who, I can rate them and note when I read them and keep personal notes. It is easy to use, and after initially loading my books, I am able to scan new books easily to add them to the collection. Highly recommend if you have a good amount of books you would like to keep track of.
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 15, 2024
Essential app for book lovers!
I have thousands of books collected over decades and the CLZ Books app helps me keep track of all of them. The CLZ team are also really helpful if I’ve ever had a query or need help with anything.
Nov 6, 2024
Love the customization
Great app for keeping a log of all your books. I love the customization. If you have a movie collection, CLZ also has an app to keep track of that.
Nov 6, 2024
A must have for every book lover!
I love this app! Was looking for a way of keeping track of my books and came across CLZ Books app. And couldn't recommend it hard enough! It is very simple to use for both populating the lists and consulting them.
Oct 12, 2024
Keep track of my library
I have always loved using this app to keep track of my home library and I'll always recommend it!
Sep 3, 2024
Keep track of what books I own
I really only use it to keep track of what books I own, so when I'm out I can check this to see if I already own a book before I purchase. It’s great for that purpose.
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!
Jun 18, 2024
Handy app
A really handy app to keep track of my ever increasing book collection. It also allows my family to check if I have a book before they buy any.
Jun 17, 2024
Highly recommended
The app does a great job of keeping track of my library. It's easy to add books, and to keep everything synced with my CLZ account in the cloud. Great support as well. I recently had an issue with the app (I couldn't add a new book), and the support team worked with me until the problem was resolved.
Mar 8, 2024
I love CLZ Books!!!
It’s the best way for me to keep track of all my books.
Feb 14, 2024
Highly recommended
I'm been using this app for a few years now. I can't begin to tell you how pleased I've been with both it's performance and completeness. If you have books, movies, and music to keep track of I highly recommend this app.
Jul 17, 2023
So easy
Makes it so easy to keep track of the books in our personal library!
Feb 20, 2023
Library
Great way to keep track of my written library.
Feb 17, 2023
I have used this app for the past 4 years as I collect manga, light novels, comics, and books. This app has been the best way for me to keep my collection organized and help me keep track of what I own. I especially like that I am able to manually add in any obscure titles that I may find into the database. I would highly recommend this app for anyone wanting to keep track of their book collection.