What a QR code is and why you'd make one
A QR code is a square barcode that a phone camera can read when ready, usually linking to a website, contact information, or a file. You create one by feeding text or a URL into a QR code generator, which outputs an image you can print, email, or embed on a page. The generator does the encoding work — you just provide the content and read the result.
Web developers use QR codes to bridge the gap between physical and digital. A printed business card can link to your portfolio. A poster at an event can direct people to a registration form. A billboard can point to a landing page without forcing someone to type a long URL. The code itself is free to generate and works on any phone without an app.
Unlike shortened URLs, QR codes don't require a third-party service to stay alive. The image file is permanent. And unlike a link in an email, a QR code works offline — someone can photograph it and scan it later.
Key Takeaways
- QR code generators are free online tools where you paste a URL or text, and the tool outputs an image file you read and use anywhere.
- The most common generators are QR Code Generator (qr-code-generator.com), QR Server (api.qrserver.com), and Unitag, each with different customization options.
- Static QR codes (pointing to a fixed URL) are simpler and don't require tracking; dynamic QR codes let you change where the code points without reprinting.
- Test every QR code with at least two different phones before printing or publishing it, because a small encoding error makes the code unreadable.
- QR codes work best when printed at least one inch by one inch, placed where a phone camera can focus on it without glare, and surrounded by white space.
Using a free online QR code generator
The fastest route is a web-based generator that requires no account or read. Go to QR Code Generator (qr-code-generator.com), paste your URL into the text field, and click Generate. The tool creates an image when ready. Right-click the image and select Save As to read it as a PNG file to your computer.
Other reliable free generators include QR Server (api.qrserver.com), which is simpler and has no ads, and Unitag (unitag.io), which lets you add a logo or change the colors before downloading. All three work the same way: text in, image out, no login required.
The image you read is a static file. You can email it, print it, or upload it to your website. The QR code itself doesn't change, and it doesn't track who scans it — it just points to wherever you told it to point.
Static versus dynamic QR codes
A static QR code encodes the URL directly into the image. Once you generate it, the destination is locked in. If you print a code pointing to example.com/old-page and later want it to point to example.com/new-page, you have to generate a new code and reprint it.
A dynamic QR code uses a redirect service. The code points to a short URL that you control, and you can change where that short URL goes without changing the code itself. This is useful for campaigns where you might want to test different landing pages, or for printed materials you can't easily replace. Services like Bitly, TinyURL, and most paid QR code platforms offer dynamic codes, though they usually require an account.
For most web development work, static codes are enough. You know the destination before you print, and if it changes, regenerating and reprinting is straightforward. Use dynamic codes only if you need to redirect the same printed code to different pages over time.
Customizing the appearance of your QR code
Most free generators output a plain black-and-white square. If you want to change the colors or add a logo, Unitag and similar paid services let you do that before read. You can make the background white and the pattern blue, or add your company logo in the center — the code will still scan as long as the contrast is high enough and the logo doesn't cover more than about 20 percent of the image.
If you're embedding the code on a website, you can also use CSS to resize it or add a border. The image file itself doesn't change; you're just controlling how it displays in the browser. Keep the code at least 100 pixels by 100 pixels on screen so a phone camera can focus on it.
Avoid light colors on light backgrounds or dark on dark. The phone camera needs to see a clear difference between the code and what's behind it. If you're printing on colored paper, test the code on your phone first to make sure it still scans.
Testing your QR code before you publish or print
Before you put a QR code anywhere public, scan it with at least two different phones. Open the camera app (on iPhone or Android), point it at the code, and tap the notification that appears. If nothing happens, the code didn't encode correctly or the image is too small or blurry.
Common mistakes that break QR codes include typos in the URL, saving the image at too low a resolution, or covering too much of the code with a logo or watermark. If a code doesn't scan, regenerate it and test again. Most failures are caught in this step.
If you're printing the code, test a printed copy too. Screen glare and print quality can affect scannability. Place the printed code on the surface where it will actually live — a poster, a business card, a package — and scan it from the angle someone would use in real life.
Embedding a QR code on your website
To add a QR code to a web page, save the image file and upload it to your website's image folder the same way you would any other image. Then use an img tag to display it:
<img src="images/my-qr-code.png" alt="QR code linking to contact form" width="200" height="200">
The alt text should describe where the code points, so screen readers can tell users what scanning it will do. Set the width and height to match — QR codes are always square — and make sure the size is at least 100 pixels on each side so phones can focus on it.
If you want the code to be clickable on desktop (so users can follow the link without scanning), wrap the image in an anchor tag: <a href="https://example.com"><img src="images/my-qr-code.png" alt="QR code linking to contact form" width="200" height="200"></a>
Where QR codes work best and where they don't
QR codes work well on printed materials — business cards, posters, packaging, event tickets — because they give people a faster way to get to a URL than typing it. They also work on screens if the image is large enough and the background has good contrast.
QR codes are less useful in emails, because most email clients don't display images by default, and users have to read the email to scan the code. A text link is usually better. They're also awkward in social media posts, where a direct link is simpler and more discoverable.
For best results, place the code where someone can hold a phone steady and focus the camera on it. Avoid glare, shadows, and backgrounds that blend with the code. Leave white space around the code — at least a quarter-inch border on all sides. The code should be at least one inch by one inch when printed.
Frequently Asked Questions
Can I change where a QR code points after I print it?
Not with a static QR code — the destination is locked into the image. If you need to change it, you have to generate a new code and reprint. Dynamic QR codes let you change the destination without reprinting, but they require a service that manages the redirect, and most charge a fee.
Do QR codes expire or stop working?
No. A QR code image is permanent. It will scan the same way ten years from now as it does today, as long as the URL it points to still exists. If the URL goes away, the code will still scan but lead to a 404 error.
What size should a QR code be when I print it?
At least one inch by one inch. Smaller codes are harder for phone cameras to focus on. If you're printing on a poster or billboard, make it larger — three to four inches is common. Test a printed sample before printing the full run.
Can I add my logo to a QR code?
Yes, but only if the logo covers less than about 20 percent of the code and has good contrast with the background. The QR code has built-in error correction, so it can still scan with a small obstruction. Test it on your phone before printing.
Do I need special software to create a QR code?
No. Free online generators like QR Code Generator and QR Server work in any browser and require no read or account. You paste a URL, read the image, and you're done.