How Do Barcode Scanners Work?

You see barcodes everywhere. From chocolate bar labels to airline boarding passes to the stickers on delivery packages, barcodes bridge the gap between physical items and digital systems. They allow retailers to maintain stock, consumers to check product details, travel companies to validate boarding passes and tickets, healthcare companies to track medicines and equipment, manufacturers trace parts, and many, many more.

They also form the foundation for a surprisingly complex set of barcode scanning processes that starts with a human scanning a label.

This guide helps you understand everything from a barcode’s technical elements to the best scanning solutions for your business. You’ll also learn why barcode scanning involves more than point-and-shoot. Rather, it’s about giving employees the right digital tools to capture the real world effectively.

Barcodes are combinations of visual patterns – lines, squares, or dots – that encode information designed for machines to read. Called barcode symbologies, they are printed or displayed on physical or electronic labels to support various use cases. They come in many different types defined by industry standards. Two examples are barcodes used by retail operations to sell consumer goods and by warehouses to help workers track package inventory.

Barcodes can include details about an item, such as price, lot number, and expiration dates for food products. Other scenarios can contain data about locations, license numbers, luggage identification, personally identifiable information (PII), and shipping manifests. Whatever the use case, barcode scanners are used to capture, process, and send this information to back-end systems.

What are the types of barcodes?

Generally, an industry or business chooses a barcode type based on the information they need to store in it , where it will be scanned, and whether any regulations apply. Two popular types are one-dimensional (1D) and two-dimensional (2D) barcodes.

1D barcodes represent data using a series of black and white bars of varying widths and spacing. These include familiar barcode types, such as the UPC codes used on consumer goods, ITF codes used for packaging materials, and UPU fluorescent barcodes for mail delivery. 1D barcodes are also called linear barcodes.

2D barcodes use more sophisticated graphics, typically blocks or a mix of bars and blocks. They include more information than 1D barcodes, such as text, price, inventory levels, and website URLs. QR codes are a familiar example of 2D barcodes, as are Aztec codes used for airline and concert tickets.

There are many ways to encode barcode data onto a visual image. The example below is from a QR code generation tool that uses generative AI to develop unusual and creative designs. The QR code is fully scannable — try it for yourself!

There are also 3D barcodes. These follow the same logic as 1D and 2D systems, but are applied to surfaces through engraving, etching, embroidery, and other methods to achieve a raised texture. Used in industries operating in harsh environments, 3D barcodes can withstand damage or removal, such as by machine washing medical uniforms or cleaning chemicals for manufacturing equipment.

3D barcodes can require specialized scanning equipment and aren’t generally found in public-facing contexts. However, Scandit’s advanced barcode scanning software enables any smart device with a camera to scan 3D barcodes.

Technical barcode standards vs. application standards

There are two types of barcode standards:

1. Technical standards, such as UPC, QR, and PDF417, define how data is encoded into visual patterns. They describe how the barcodes physically work rather than how they are used across different use cases.
2. Application standards, such as GS1 and GTIN, specify how barcodes should be used by an industry. They are independent of technical standards, but they may refer to them or define a subset of a technical standard for a specific use case.

For scanning devices and software to work correctly, they must understand the appropriate technical standards when deciphering the visual patterns on barcode labels. Not doing so means the scanner cannot decode barcode data. Application standards ensure the barcodes you use will be accepted across your industry and comply with industry regulations.

What do the patterns on a barcode mean?

Unless you’re an android, you probably can’t understand what data a barcode contains by just looking at it. Every barcode standard applies different meanings to its patterns of lines, squares, and dots. Here are two examples to demonstrate how complex they are and why it’s important for a scanner to know the standards to process encoded data correctly.

Characteristics of a UPC barcode

A UPC code is a 1D barcode symbology characterized by a series of vertical stripes with a set of numbers printed underneath. They encode GTIN information using 12 (UPC-A) or 6 (UPC-E) numerical digits. UPC-A follows this pattern:

1. First 6 – 10 digits: The GS1 Company Prefix which is the business identification number assigned by GS1.
2. Next 1 – 5 digits: The item number assigned by the business.
3. Last digit: A mod 10 checksum used by scanning software to detect errors.

Characteristics of a QR code

A QR, or Quick Response barcode, is a 2D symbology of dark or light-colored squares arranged in a square grid on a contrasting background. They encode up to 4,296 alphanumeric characters, 7,089 numerical characters, 2,953 bytes of information, or 1,817 Kanji characters.

This makes QR codes extremely versatile. The video below shows a user scanning a QR code to activate their smartphone temporarily as an ID scanner to improve ergonomics (using Scandit’s ID Bolt product).

A standard QR code contains six components:

1. Quiet Zone: The empty white border on the outside of a QR code. Scanners use this to distinguish between the QR code and unrelated outside elements.
2. Finder pattern: Three large squares at the bottom left, top left, and top right corners of the QR code. Barcode scanners use these squares to identify a QR code and interpret everything inside as QR code data.
3. Alignment pattern: A small square near the bottom right corner that barcode scanners use to orient the code properly, even when skewed or at an angle.
4. Timing pattern: This is an L-shaped line that runs between the squares of the finder pattern. This helps the barcode scanner identify individual squares within the whole pattern and allows a damaged QR code to be read.
5. Version information: Data encoded near the top–right finder pattern square to identify the version of the QR code (numeric, alphanumeric, binary, or Kanji).
6. Data and error correction cells: The remainder of the QR code contains the application-specific information, including error correction blocks that allow scanners to work even if 30% of the code is damaged.

Printed vs. digital barcode labels

Barcodes are commonly printed on physical media and attached to items, but many industries have replaced them with digital versions. Electronic shelf labels (ESLs) are one example of tiny digital displays that use electronic paper or LCD screens to show product information, prices, and other details.

ESLs are typically attached to the front edge of retail shelves and connect to a store’s ERP system for real-time updates. This improves pricing accuracy, reduces pricing management labor costs, and supports the growing dynamic pricing trend.

Some retailers use both printed and digital barcodes throughout their supply chains. This impacts their choice of barcode scanner, as older models of laser scanners may not be able to read digital displays.

Additionally, many retail products (such as cosmetics) use tiny barcodes that are hard to scan without advanced scanning software. Camera-based solutions typically offer the flexibility to support both of these scenarios.

Each type of barcode scanner has advantages and limitations, depending on where and how they are used. The most common types are:

• Pen wands: When drawn across a barcode, these devices detect changes in reflected light as it passes over the dark and light areas. As they require close contact with labels, pen wands are ideal for low-speed, low-volume scanning as scans require more effort from users.
• Laser scanners: These devices sweep multiple laser beams across barcodes to detect changes in reflected light. Modern laser scanners often employ a multi-line or omnidirectional scanning pattern to read barcodes in various orientations. They are ideal for higher scanning volumes but require precise aiming of labels one by one and can get confused by glare and reflective surfaces. They also tend to be bulky and have limited functionality compared to other scanner types.
• Charge-coupled device (CCD) readers: Also known as LED scanners, these devices capture an electronic image of the barcode and analyze it using software. They tend to be physically durable but their narrow capture range means users spend more time scanning.
• Camera-based scanners: These devices read barcodes using digital image sensors (such as smartphone cameras, tablets, handheld computers, and drones), and image processing software. They tend to support the broadest range of barcode types and adapt to many situations, such as low-light environments, damaged barcodes, and awkward scan angles. When running on smart devices, the image-based data sources and additional processing power often support additional capabilities, such as scanning multiple barcodes at once and adding augmented reality (AR) overlays to guide users in ways the other scanner types cannot support (such as the example shown below).

Each type of barcode scanner captures and processes label data differently, but they usually follow these steps:

1. Initial capture: The scanner’s sensor captures the barcode’s light and dark patterns, much like taking a photo. Laser scanners and CCD readers emit light and capture reflections. Camera-based scanners capture the existing light entering their lenses.
2. Signal conversion: The scanning device’s sensor transforms light into electronic information through the photoelectric effect. The scanner’s light sensor or camera generates different electrical currents based on the intensity of reflected light it receives. These currents correspond to the barcode’s pattern.
3. Digital decoding/image processing: The electrical currents are converted into digital form to create a binary representation of the barcode’s pattern. Just as a human interpreter needs to understand a language to translate it, the processing method must understand the barcode’s standard to interpret the patterns it receives accurately.
4. Data processing and display: The binary data is transformed into user-facing formats, such as a device’s display or ERP database.

More advanced barcode scanning technologies build on these steps to add value to users. For example, Scandit software employs Smart Label Capture (shown in video below) to give users only the data they need from complex labels with multiple barcodes and text fields — such as labels containing serial numbers, weights, or expiry dates. This avoids giving users extraneous information and having to scan different types of data separately.

In addition to the technical aspects of how barcode scanners work, user experience has a significant influence on the overall scanning workflow. The following image illustrates barcode scanning from the user’s perspective, including aiming their device, barcode capture, and viewing results. Inefficiencies and inaccuracies at any step can cause significant user delays and frustrations – especially in high-volume scanning environments.

When choosing a barcode scanner for your business, consider how it can manage or eliminate the following common issues.

Lack of symbology support

Organizations often discover too late that their chosen scanning solution doesn’t support all the barcode types they need to process. This is especially prevalent in retail and logistics, where workers must scan barcodes from different suppliers, industries, and geographies.

When a scanner encounters an unsupported barcode type, workers resort to manual data entry, which causes delays and potential errors.

To avoid this issue, you should validate any scanning solution against all the barcode symbology requirements for your business. Ideally, your solution supports a greater number of symbologies, so you don’t have issues if your business adopts them later.

Degradations due to environmental conditions

The physical environment where scanning occurs can significantly impact a barcode scanner’s performance. Warehouses can subject scanners to low-light and high-glare situations. Retail stores must contend with varying humidity levels and occasional impacts from drops or mishandling.

These factors can reduce scanner lifespan, increase maintenance costs, and cause scanning failures that frustrate users and slow operations. Your barcode scanner implementation must account for these conditions through appropriate hardware selection and software that can adapt to them.

Poor scanning performance

Multiple interconnected factors influence barcode scanner performance. Scan speed and accuracy vary significantly based on barcode quality, number, distance, angle, and environmental conditions. User experience also plays a role, as the harder it is to locate and scan a label, the slower it takes. When scanners fail to read barcodes on the first attempt, workers must spend more time repositioning items or making multiple scanning attempts.

These small delays and errors can add up to significant productivity losses in high-volume operations. Many barcode scanning solutions employ software-based measures to overcome these issues, such as allowing wider scan angles and longer scanning distances or employing performance optimization techniques.

More advanced scanning tools improve performance through richer and more helpful user experiences. For example, if workers are scanning one barcode while others are in view, techniques such as context-based scanning (see video below) help them capture the right one.

Connectivity issues

Some scanning solutions rely heavily on network connectivity to function effectively – including sending label data off the device for processing When connections become unstable or fail, such as a last-mile delivery in a remote location, workflows can grind to a halt.

Barcode scanners that support offline operation are best able to solve this problem. There are many approaches to this, from storing captured data until connectivity is reestablished with a cloud processor to performing all decoding and processing on-device. The latter approach has the added benefits of uninterrupted scanning workflows and improved security by not transmitting data off the device.

User experience struggles

Scanning performance depends just as much on the scanner’s ease of use as on its processing algorithms. User adoption rates also depend on how more or less frustrated users are by the scanner’s interface. If not designed with humans in mind and without the tools for developers to improve user experience, workers will struggle with poor ergonomics and unintuitive controls – leading to frustration and slower workflows.

Choosing barcode scanning solutions that prioritize user-centered design helps overcome user experience and adoption issues. The below image shows Scandit SparkScan, a pre-built barcode scanning component with a scanning interface that floats on top of any existing UI. It allows users to efficiently and comfortably scan from any angle and aim quickly using the device itself.

The development of context-based scanning technology makes users’ lives even easier. Through advanced AI algorithms, this technology anticipates and captures the user’s target barcode even when there are multiple barcodes clustered in the sensors’s field of view. Scandit’s Smart Scan Intention employs this technology to reduce unwanted scans by up to 100%.

Integration problems

Integrating barcode scanning systems with existing business software can present technical challenges. Legacy scanners may use incompatible data formats or lack modern APIs for real-time data exchange. Open-source solutions may not support the development frameworks your team uses or lack the documentation and professional help necessary to get things running under high-volume workloads.

Integration challenges can lead to delayed deployment, data errors, and increased support costs. You can avoid these problems by working with barcode scanner providers who understand the realities of enterprise environments and offer support to get scanning deployed quickly and correctly.

To learn more about these common issues and others, read our blog on how to solve common barcode scanning challenges.

Scandit’s camera-based scanning solutions are purpose-built to overcome many common pain points associated with barcode scanning: performance, usability, and integration effort. Advanced computer vision algorithms and user-focused design mean you get a barcode scanning solution that ensures items are captured and tracked accurately under real-world conditions.

Additionally, Scandit’s SDKs include features that improve barcode scanning performance for high-volume use cases. For example, workers can finish inventory faster by scanning multiple items simultaneously using MatrixScan Count’s augmented reality (AR) overlays. Or, delivery drivers can find the right parcel from a full shelf using MatrixScan Find’s AR interface.

To learn more about these and other barcode scanning solutions, read our barcode scanning product brochure, including options for no-code, pre-built, and custom deployments.

Case study: Barcode scanning in action

The best way to understand how barcode scanners work is to learn from a company that deployed them successfully.

VF Corporation, one of the world’s largest apparel, footwear, and accessories companies, increased revenue by switching to Scandit barcode scanning to manage inventory levels accurately. By eliminating stock shortages, they now serve more omnichannel orders, increasing revenue and customer satisfaction.

Discover Scandit's barcode scanning software

Scandit enables over 50 billion fast, accurate and secure scans every year, and we’re trusted by six of the top ten global brands. Ready to join them? Our technology is easy to test for yourself with full-featured free trials and simple, fast and free demo apps.

Can smart device barcode scanners read damaged or worn barcodes?

Advanced barcode scanners can read damaged and worn barcodes, assuming enough label information is visible and decipherable by their decoding algorithms. The minimum amount of information required depends on the sensor’s capabilities, software sophistication, and environmental conditions.

Scandit’s barcode scanning software employs advanced computer vision techniques and other methods to scan barcodes in all types of conditions. This includes damaged or worn barcodes and small or unusual barcodes.

What types of barcodes can be scanned using Scandit’s software?

Scandit’s solution can scan all major barcode types used worldwide, including 1D symbologies, 2D symbologies, and composite codes. You can read the full list on our barcode symbologies page.

How does Scandit's barcode scanning technology handle low-light conditions?

Scandit’s barcode scanning technology is designed and tested for extreme low-light conditions. Using advanced decoding algorithms, Scandit software can take low-light captures and extract symbology data with enough precision to achieve successful results in various environments.

Are there any specific system requirements for using Scandit’s barcode scanning software?

Scandit software is compatible with more than 20,000 types of smart devices, including older or lower-end devices that don’t come with an autofocus feature. It’s also available on all common development frameworks and operating systems.

For detailed specifications, read our system requirements.

How secure is the data captured by Scandit’s barcode scanning solutions?

Scandit’s solutions are designed with security in mind. All barcode capture and image processing is performed on the scanning device to ensure high availability and confidentiality. Any data shared with Scandit is encrypted both during transit and at rest.

Additionally, Scandit is ISO 27001:2022 Certified and has a dedicated information security team and executive-level oversight committee.

Can Scandit’s software be integrated with existing inventory management systems?

Yes, one key benefit of Scandit’s solution is that it supports high-performance and accurate barcode scanning for inventory management. For high-volume operations, Scandit offers MatrixScan Find, which scans multiple barcodes simultaneously, guided by an AR overlay, and MatrixScan Count, a pre-built scan and count solution for counting inventory and receiving multiple items at once.