QR Codes Explained: How They Work and What They Can Store

What Is a QR Code?

A QR code is a two-dimensional machine-readable pattern that can represent text or structured information.

A compatible camera or QR scanner reads the pattern, decodes its contents, and may then offer an action based on the encoded data.

How Does a QR Code Work?

A QR generator converts input data into a matrix of dark and light modules.

A scanner identifies the QR structure and converts the pattern back into its encoded content.

The receiving application decides what to do next. For example, it may:

• Display text.
• Offer to open a website.
• Open an email application.
• Offer to call a phone number.
• Offer to connect to a WiFi network.

What Can the ExaHubs QR Generator Create?

The current ExaHubs QR Code Generator supports five content types:

QR Codes for Text

A text QR code contains the exact text entered into the generator.

Possible uses include:

• Short instructions.
• Reference numbers.
• Event information.
• Simple messages.
• Offline notes.

Remember that anyone who scans a publicly displayed QR code can potentially read its content.

QR Codes for Website Links

URL QR codes are among the most common types.

In the current ExaHubs generator, if a URL does not begin with http:// or https://, the tool adds https:// before generating the QR content.

For example:

Test the final code before printing it to make sure the destination address is correct.

QR Codes for Email Addresses

The current generator creates email QR content using the mailto: format.

A compatible scanner may offer to open the device's email application with that address as the recipient.

QR Codes for Phone Numbers

Phone QR codes use the tel: format.

A compatible smartphone may offer to call the encoded number.

Include the appropriate international country code when the QR code may be used by people in different countries.

QR Codes for WiFi Networks

A WiFi QR code can make it easier for visitors to join a wireless network without manually typing the network name and password.

The current ExaHubs generator allows:

• WiFi network name (SSID).
• Password.
• WPA/WPA2 security.
• WEP security.
• No-password networks.

The tool also escapes special WiFi characters when constructing the encoded value.

Be Careful with WiFi QR Codes

Static QR Codes

A normal QR code directly contains its encoded value.

If you create a QR code containing a specific URL and later change the website address, the original QR code still contains the old URL.

This is different from some commercial dynamic QR systems where a redirect destination can be changed later.

Does a QR Code Automatically Track Scans?

No. The QR pattern itself does not automatically provide analytics.

Tracking generally requires a destination or service designed to record visits or scan-related activity.

If you want to understand this distinction in more detail, read the ExaHubs QR Code Tracking Guide.

QR Code Size

A QR code must be large and clear enough for the intended scanning distance and medium.

A QR code displayed on a phone screen has different requirements from one printed on a poster viewed from several feet away.

The ExaHubs interface allows the displayed QR size to be selected before previewing the generated result.

Contrast Matters

Strong contrast between the QR code and its background generally makes scanning more reliable.

Avoid designs where:

• The foreground and background are too similar.
• The QR code is placed over a busy photograph.
• The edges are cut off.
• The code is blurred or distorted.

Leave Space Around the QR Code

QR codes normally need clear space around their outer boundary so a scanner can distinguish the code from nearby graphics or text.

Avoid placing important design elements directly against the QR pattern.

Why Does ExaHubs Download QR Codes as SVG?

The current ExaHubs QR Code Generator receives an SVG representation from its QR API and allows the generated code to be downloaded as:

SVG is a vector format, so it can usually be scaled more cleanly than a small raster image.

This can be useful when preparing QR codes for websites, documents, cards, or print layouts.

How ExaHubs Generates the QR Code

The current page prepares the QR content in the browser and then sends it to the ExaHubs QR generation API.

After generation, the returned SVG is displayed in the browser and can be downloaded by the user.

This means we should not describe the current QR generation process as completely browser-only.

Always Test Before Printing

A QR code that looks correct can still point to the wrong destination if the encoded input contains a mistake.

Before printing hundreds of copies:

1. Generate the QR code.
2. Scan it with at least one phone.
3. Verify the exact destination or content.
4. Test another device when possible.
5. Print one sample.
6. Scan the printed sample.
7. Only then produce the final quantity.

Preparing a QR Code for Print

For printed materials:

• Use a clear, high-quality source.
• Maintain adequate physical size.
• Keep strong contrast.
• Avoid cropping the edges.
• Leave clear surrounding space.
• Test the actual printed version.

Where Can QR Codes Be Used?

Common examples include:

• Business cards.
• Restaurant menus.
• Flyers.
• Posters.
• Product packaging.
• Event signs.
• Profile pages.
• WiFi guest cards.
• Contact materials.

Scan QR Codes Carefully

QR codes can hide the visible destination from someone looking only at the printed pattern.

When scanning unfamiliar codes:

• Review the destination shown by your phone before opening it.
• Be cautious with unexpected login pages.
• Check the website domain carefully.
• Avoid submitting sensitive information to suspicious destinations.

How to Use the ExaHubs QR Code Generator

1. Open the QR Code Generator.
2. Select the QR type.
3. Enter the requested content.
4. For WiFi, enter the SSID, password, and security type.
5. Choose the desired display size.
6. Select Generate QR Code.
7. Scan and verify the result.
8. Download the SVG when needed.

Common QR Code Mistakes

Encoding the wrong URL

A perfectly readable QR code is still useless if the destination is incorrect.

Printing too small

QR size should match the intended scanning distance.

Poor contrast

Decorative colors can reduce reliability when foreground and background are too similar.

Publishing private WiFi credentials

Treat a WiFi QR code containing a password as credential-sharing material.

Assuming scan tracking happens automatically

QR generation and QR analytics are separate concepts.

Never testing the printed code

Always test the final physical version before large-scale printing.