Codabar, also called NW-7, is a numeric 1D barcode that starts and ends with one of four letters: A, B, C or D. barKoder reads Codabar labels on library books, blood bags and airbills with the phone and tablet cameras in your iOS, Android and web apps.
| Type | Discrete, self-checking linear (1D) symbology. Each character has 7 elements, 4 bars and 3 spaces, each narrow or wide. |
| Character set | Digits 0-9 and the symbols - $ : / . +. The letters A, B, C and D are used only as start and stop characters (some specifications label them T, N, * and E). barKoder includes them in the result, for example A40156B. |
| Capacity | Variable length. Each application sets its own data length. |
| Check digit | None required, because every character is self-checking. Some applications add an optional check digit, often modulo 16. |
| Standard | AIM Uniform Symbology Specification Codabar (ANSI/AIM BC3). Known as NW-7 in Japan (JIS X 0503). |
| Typical uses | Library books and cards, blood bank labels (ABC Codabar), photo labs, FedEx airbills |
Codabar is one of the oldest barcode symbologies. It was developed in 1972 at Pitney Bowes, and its other names include NW-7, USD-4, Monarch and Code 2 of 7. It was designed for retail price labels, then found its long-term home in libraries, blood banks, photo labs and courier airbills.
A Codabar symbol has five parts:
The start and stop letters frame the data, and the 16 possible start/stop pairs can tell one application's labels from another's. Because each character is self-checking, Codabar needs no check digit, though some systems add one.
Every Codabar reader decodes the same characters. What differs between labels is the choice of start and stop letters, the bar widths and the data format.
| Variant | What it is | Scanning notes |
|---|---|---|
| Start/stop A-D | Any of the four letters can start or end the symbol. Some specifications call them T, N, * and E. | Use the letters to check that a label belongs to your application |
| Traditional Codabar | The original Pitney Bowes design, with wide-to-narrow ratios varied so every character has the same width | Same decoder |
| Rationalized Codabar | Uses one fixed wide-to-narrow ratio, so character widths vary | Same decoder |
| NW-7 | The Japanese name for Codabar, standardized as JIS X 0503 | Same symbology, same characters |
| ABC Codabar | The blood bag label adopted in 1977. Replaced by ISBT 128 in many countries. | Hospitals may still meet both label types |
| FedEx airbill | A 12-digit tracking number plus a format ID, starting with C and ending with D | The airbill check digit algorithm is not public |
Codabar survives where large numbers of labels were printed long ago and are still in circulation.
US blood banks introduced the ABC Codabar blood bag label in 1977. ISBT 128 later replaced it, and AABB required ISBT 128 by May 2008, but hospitals handled both label types for years during the switch. Apps that read older bags and lab forms still need Codabar.
Barcode scanning for healthcare →Libraries adopted Codabar soon after 1972 to speed up check-outs and returns, and it still has a large installed base on books and library cards. Scan a whole shelf of book labels at once with Batch MultiScan.
Barcode scanning for education →Codabar was built to print reliably on dot matrix printers, which made it a fit for multi-part forms such as FedEx airbills. The FedEx variant starts with C and ends with D.
Barcode scanning for logistics →The barKoder Barcode Scanner SDK reads Codabar on iOS, Android, the web, Windows and Linux, and in Flutter, React Native, .NET MAUI, Capacitor, Cordova and NativeScript apps. These features matter most for this code.
Reads all supported 1D barcodes with strong deformation, such as labels wrapped around test tubes and bottles or wrinkled forms, where no straight line crosses all the bars.
Segment Decoding →Decodes several barcodes in one camera view, whatever their type or size. The feature page names library bookshelves as a use case: capture the labels on many books in one pass.
Batch MultiScan →Codabar has no fixed length, so set the minimum and maximum length your labels use. The Web SDK method is setLengthRange, which sets the minimum and maximum length to be detected.
Enable only the decoders you need. This Web SDK call enables Codabar, using the decoder constant from the barKoder docs.
Barkoder.setEnabledDecoders(Barkoder.constants.Decoders.Codabar);On Android the same decoder is Barkoder.DecoderType.Codabar.
Decoder lists for other platforms: Android general example and Android API reference.
Install the free barKoder demo app, or open the web demo, and scan your own Codabar labels before you integrate the SDK. To read a single code from a photo or screenshot, use the free online barcode scanner.
iPhone and iPad
Scan with your camera, or point it at the QR code to open the App Store.
Android phones and tablets
Scan with your camera, or point it at the QR code to open Google Play.
Any modern browser
Runs the Web SDK in your browser, on desktop or mobile, with nothing to install.
Test with known samples. Print or display the testing sheet and scan each 1D and 2D barcode with the demo app. The data sheet summarizes the SDK for your team.
Verified credentials
Certified information security management built around internationally recognized controls.
Official Solution Provider supporting standards-based barcode and data-capture workflows.
Solution Provider listing covering barcode, mobile application and 2D barcode capabilities.
Discover the barKoder Web SDK listing and connect through Microsoft Marketplace.
Registered Independent Software Vendor in Zebra's PartnerConnect ecosystem.
Codabar is a linear (1D) barcode symbology developed in 1972 at Pitney Bowes. It encodes the digits 0-9 and six symbols (- $ : / . +) between a start and a stop letter, A, B, C or D. It is also called NW-7, USD-4, Monarch and Code 2 of 7. Libraries, blood banks, photo labs and courier airbills have used it for decades.
Every Codabar symbol begins with one of the letters A, B, C or D and ends with one of them. They frame the data and never appear inside it. The start and stop letters do not have to match, so there are 16 possible pairs, and some systems use the pair to identify the type of label. FedEx airbills, for example, start with C and end with D. Some specifications name the four characters T, N, * and E instead.
Not by default. Each Codabar character is self-checking, so the standard does not require a check digit. Some applications add one before the stop character, most often a modulo 16 check digit. If your labels carry one, validate it in your app after the scan.
Codabar encodes only digits and six symbols, with A to D as start and stop characters. Code 39 also encodes the uppercase letters A to Z, a space and a few more symbols, and always starts and ends with an asterisk. Code 39 is common in industry and government labeling, while Codabar lives on in libraries, blood banks and airbills. barKoder reads both.
NW-7 is the name for Codabar in Japan, where it is standardized as JIS X 0503. Rationalized Codabar uses one fixed ratio between wide and narrow elements, while the original design varied the ratio so every character had the same width. Both are the same symbology with the same characters, so one decoder reads them.
Test the SDK on your own library, blood bank and airbill labels with a free 30-day trial, or talk to an SDK expert about your project.
Code 39
Code 11
Code 93
Code 128
MSI Plessey
Telepen