Technology

What is PDF417? Breaking down the most common ID barcode

December 14, 2022
What is PDF417? Breaking down the most common ID barcode

You may not know it by name, but you’ve seen it everywhere. On your boarding pass at the airport, a postal package, and the back of your government-issued ID. 

Known as PDF417, it is defined as a stacked linear barcode and used in several commercial and government applications. Coincidentally, PDF in this case stands for “portable data file,” which is similar to (but not the same as) the widely used Adobe file that stands for “portable document format.” The numbers 417, meanwhile, represent the code’s pattern, which consists of four bars and spaces and a 17-part codeword. 

Now that we’ve cleared that up, why is the PDF417 barcode still relevant — particularly in the identity document universe? In a world where QR codes are being scanned left and right, the older PDF417 (first introduced in 1991) is likely not going anywhere for a while.

Why was PDF417 created? 

While barcodes had existed for nearly 40 years before PDF417, they were tasked with storing smaller amounts of data. The greatest example being the universal product code (UPC), which you can find on almost all consumer packaged goods. 

PDF417, meanwhile, ushered in a new wave of 2D barcodes that could store more data per unit area. Instead of just storing the alphanumeric data needed to classify a specific product, PDF417 is able to represent complex data strings, including binary code, special characters, images, signatures, and even fingerprints. 

As a result, the use cases for PDF417 expanded far beyond the retail world, and into more complex sectors like logistics, travel, inventory management, postal services, and government identification. 

PDF417 vs QR Code vs Data Matrix

PDF417 is considered a 2D barcode, even though it more closely resembles traditional linear barcodes (like the aforementioned UPC) due to its left-to-right alignment that includes vertical lines, of varying width and distance, on both ends. In the middle, however, are the data codewords that give PDF417 its 2D perspective. For this reason, and due to its high data density, PDF417 is grouped with other prominent 2D barcodes, namely QR (quick response) code and Data Matrix. 

While these three codes are all classified as 2D, they are unique in their composition, data capacity, and use cases. As we’ve already discussed, PDF417 may look like a typical rectangular barcode you scan at the supermarket, but can hold substantially more (and complex) data. Both QR Code and Data Matrix appear in square-form, although they differ in how much data they can store, their size, and how they are read.

Data Matrix is unique for being the smallest physically of the three codes, while still offering high data density. As a result, Data Matrix is the regulated standard for healthcare items (e.g., pill containers) and is used for other products where space is limited, like electronic components. 

A QR Code, on the other hand, is typically larger in physical size, but can hold the most data of the three. Additionally, almost all smartphone cameras can capture QR codes, making them ideal for consumer-facing mobile applications. While some smartphones can read Data Matrix and PDF417 codes, a consumer will typically need a third-party extension to do so.

PDF417 can store a lot of data, although the capacity is less than that of Data Matrix and QR codes. However, all three codes use the Reed-Solomon algorithm for error detection and correction, allowing them to be read at varying levels of damage. 

PDF417 in Identification Documents 

One of PDF417’s most prominent use cases is being printed on an array of identity documents. Prime examples include US driver’s licenses and identification cards, as PDF417 is the barcode standard used by the Department of Homeland Security when issuing state IDs. As a result, PDF417 barcode reader software is always in high demand. 

Essentially, all of the information you see on the front of your ID card is embedded in the PDF417 code located on the back. Since PDF417 codes can be found on the ID cards and passports of several countries, the ability to read them accurately is essential for any organization performing identity verification, especially on a diverse user base. Due to the high density of data they store, most typical barcode readers are incapable of being accurate PDF417 decoders.

With the prominence of PDF417 codes across global IDs, many companies are tasked with decoding them in order to verify the identity of their users, whether they’re customers, employees, applicants, or otherwise. However, not all PDF417 reader apps are created equal. While it might be possible to find a PDF417 scanner for Android in the Google Play store, there is no guarantee that the software is safe or easy to navigate for end-users.

For a PDF417 reader to be a true differentiator, data extraction must be possible in real time during user onboarding. Documents can be analyzed for authenticity and being physically present, while the user’s identity is also verified through a biometric scan. Doing so helps keep your company and users safe and secure, protecting them against different types of identity fraud attacks. 

It’s all too easy to generate false barcodes these days, with PDF417 generator apps being accessible to anyone, enabling fraudsters to create fake IDs. With proper document verification in place, however, codes can be thoroughly analyzed to determine if they are authentic. This is why identity verification is so important; yes, documents can be falsified, but the truth can be unearthed by a robust solution that takes a holistic approach — powered by accurate and real-time data.

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