A small square that carries useful information
QR codes connect a physical object or on-screen image with digital information. A camera reads the pattern, decodes its contents, and offers the relevant action—such as opening a page, joining Wi-Fi, or preparing a message.
The pattern itself is only a carrier. A reliable result depends on what was encoded, how clearly the code is displayed, and whether the destination or contact details remain valid.
What is a QR code?
QR stands for Quick Response. A QR code is a two-dimensional barcode made from dark and light square modules arranged in a grid.
Unlike a familiar one-dimensional barcode, it carries information across both directions. A QR code can encode a URL, plain text, contact actions, message details, Wi-Fi credentials, and other structured data—not only website links.
How does a QR code work?
Generation turns information into a matrix. Scanning reverses that process and lets the device decide what action the decoded content represents.
Anatomy of a QR code
Not every square carries your message. Structural patterns help the scanner find, orient, and sample the matrix; the quiet zone separates it from surrounding content.
QR code vs traditional barcode
Both encode machine-readable data, but their structure and common uses differ.
| Feature | QR code | Traditional barcode |
|---|---|---|
| Dimensions | Two-dimensional matrix | One-dimensional bars and spaces |
| Reading | Read as an image and oriented by corner patterns | Typically read across the bars |
| Content | Can carry text and structured actions such as URLs | Often identifies an item through a shorter code |
| Typical use | Links, access, tickets, information and workflows | Retail, inventory and product identification |
Static and dynamic QR codes
The visible pattern can look similar, but the destination is managed differently.
The final data is encoded directly in the matrix. It cannot be edited after generation. The downloaded CoreBase QR code is static and does not depend on a CoreBase redirect.
The code usually points to an intermediary link managed by a service. That service may allow the destination to change, but the code then depends on its infrastructure and terms.
What information can a QR code contain?
A QR matrix stores data. The scanning app interprets that data and offers an action when it recognizes a supported format.
Open a website or show plain information.
Prepare an email, phone call, or SMS.
Provide Wi-Fi network name, security setting, and password.
Tickets, identifiers, payments, and app actions can use QR codes, depending on the encoded standard and reader.
QR types available in CoreBase
CoreBase currently generates six static QR content types. The data is prepared and rendered in your browser.
Encodes a web address.
Scanning offers to open the destination in a browser.Encodes plain text without requiring a web page.
Scanning displays the stored information.Encodes an address with an optional subject and message.
Scanning prepares a new email in a compatible app.Encodes a telephone number.
Scanning offers to start a call.Encodes a recipient and optional message.
Scanning prepares a text message.Encodes a network name, security type, and password.
Scanning offers to join the network on supported devices.Which QR code do you need?
Start with the action you want after scanning.
How to create a QR code
A short workflow is usually enough. The final test matters as much as generation.
- Choose the QR type
Match the type to the action users should take.
- Enter the information
Check URLs, contact details, and Wi-Fi credentials before generating.
- Generate the code
Use clear foreground and background colors with strong contrast.
- Test it
Scan with more than one device when the code will be widely distributed.
- Download the right format
Use PNG for convenient raster output or SVG when scalable vector artwork is useful.
PNG or SVG?
CoreBase supports both formats. Choose according to where the code will be used.
A raster image that is convenient for websites, presentations, social posts, and common documents. Export it at a suitable pixel size instead of enlarging a small file later.
A vector file that scales without losing edge sharpness. It is often the better starting point for print layouts and design software.
QR codes for print
Print quality, placement, and expected scanning distance determine whether a code is comfortably usable.
- Give the code enough physical space for its modules to remain distinct.
- Keep strong contrast between the code and its background.
- Preserve a clear quiet zone around every side.
- Scale proportionally; do not stretch or skew the matrix.
- Keep important artwork away from the modules.
- Test the final printed item at the distance and lighting users will encounter.
Why a QR code may not scan
Most failures come from presentation, damage, capture conditions, or an invalid destination rather than the idea of QR itself.
Individual modules cannot be captured clearly.
The reader cannot reliably separate dark and light areas.
Nearby text or graphics interfere with symbol detection.
Stretching changes the geometry the decoder expects.
Too much of the matrix is missing despite error correction.
The code may decode correctly while its URL or action no longer works.
Do QR codes expire?
A static QR code has no built-in expiry date. Its encoded modules do not change after the code is created.
The resource inside can still become unusable: a page may be removed, a domain can lapse, Wi-Fi credentials can change, or a phone number may be retired. A dynamic code can also stop working when its redirect provider or subscription is unavailable.
Do QR codes need the internet?
Decoding and completing the action are separate steps.
| Do QR codes need the internet? | What information can a QR code contain? |
|---|---|
| Plain text | No connection is needed to read the stored text. |
| Phone or SMS | The data can be decoded offline; sending or calling depends on the device and network. |
| Website URL | The address can be decoded offline, but loading the page normally needs internet access. |
| Wi-Fi | The device can read the credentials and join the encoded network without first opening a web service. |
Use QR codes with ordinary link awareness
A QR pattern does not show its destination as clearly as printed text. Treat an unfamiliar QR code as you would an unfamiliar link.
- Review the displayed destination before opening it when your device provides a preview.
- Be cautious with stickers or replacement codes in public places.
- Do not enter sensitive information on a page that looks unexpected or suspicious.
- Organizations should inspect physical QR placements periodically for tampering or damage.
Practical QR code uses
The format is useful wherever a short scan removes typing or connects physical material with a digital action.
- Restaurant menus and venue information
- Event tickets and check-in
- Guest Wi-Fi access
- Business cards and contact details
- Product packaging and instructions
- Posters, presentations, and feedback forms
- Education and classroom resources
- Payments when a compatible payment standard is encoded
Frequently asked questions
Are QR codes free to create?
A static QR code can be generated without an ongoing service. CoreBase creates and downloads supported static codes without an account.
Do QR codes expire?
Static QR codes do not contain an expiry date, but the encoded destination or details can stop being valid.
Can a QR code work without internet?
The device can decode it offline. Internet is needed only when the resulting action, such as loading a website, requires a connection.
Can I change a QR code after printing it?
Not when the final data is encoded directly in a static QR code. A dynamic redirect can be changed through its provider.
What is the difference between static and dynamic QR codes?
Static codes contain the final data. Dynamic codes commonly contain a managed redirect whose destination can be updated.
Why is my QR code not scanning?
Check size, sharpness, contrast, quiet zone, distortion, damage, and whether decorative elements cover modules.
Is SVG or PNG better for printing?
SVG is usually easier to scale cleanly. A sufficiently large, high-quality PNG can also work for a known print size.
Can QR codes contain more than website links?
Yes. They can carry text and structured data for email, phone, SMS, Wi-Fi, and other compatible actions.