QQudo Tools

QR Code Generator

Generate QR codes for URLs, text, Wi-Fi, contacts and more. Customize colors, styles and logo. All processing is done locally in your browser.

🔒QR codes and logos are processed in your browser. Nothing is uploaded to Qudo servers.

https:// will be added automatically if missing.

Size

QR codes need white space around them to be scannable.

Style ▼

Complex styles may reduce scanning accuracy. Test after generating.

Logo ▼

Preview

Enter content to generate a QR code here.

QR Code Generator

This tool generates QR codes for URLs, plain text, Wi-Fi credentials, email, phone numbers, SMS, contact cards (vCard), geographic locations, calendar events, and custom content. You can customize colors, module shapes, finder patterns, add logos, and generate QR codes in batch. All processing is done entirely in your browser.

How to Use

  1. Select the QR code content type (URL, text, Wi-Fi, etc.).
  2. Fill in the content fields.
  3. Adjust size, colors, and error correction level.
  4. Optionally upload a logo image.
  5. Check the verification status to ensure the QR code is scannable.
  6. Download in PNG, SVG, or WebP format.

Error Correction Levels

QR codes support four error correction levels: L (7% recovery), M (15% recovery), Q (25% recovery), and H (30% recovery). Higher levels allow more of the QR code to be damaged while still being scannable. When adding a logo, level H is recommended because the logo covers part of the QR code data.

Static QR Codes

This tool generates static QR codes. The content is directly encoded into the QR code pattern. Once generated, the content cannot be changed remotely. There is no redirect server and no scan analytics. If the original URL becomes invalid, the QR code will no longer work for that purpose. The advantage is that static QR codes never expire and have no dependency on any service.

How to Improve Scanning Success

  • Use dark foreground on light background for best contrast.
  • Keep sufficient quiet zone (margin) around the QR code.
  • Do not make the logo too large (under 20% of QR area).
  • Do not stretch or distort the QR code.
  • Test scan before printing in bulk.
  • Test with multiple scanner apps to ensure compatibility.

Size Recommendations

For screen display, 256x256 pixels is usually sufficient. For business cards, use at least 512x512 pixels. For labels and stickers, 1024x1024 is recommended. For posters and large prints, use 2048x2048 or higher. The actual printed size should be chosen based on scanning distance - farther distances require larger codes.

Privacy

All QR code generation, logo processing, and verification are done entirely in your browser. No data is sent to any server. Wi-Fi passwords, phone numbers, contacts, and URLs are never stored or transmitted.

Limitations

QR codes have a maximum data capacity that depends on the error correction level and content type. Complex styles (rounded modules, dot patterns) may reduce scanning accuracy on some devices. Low color contrast can prevent scanning. Print quality and paper texture may affect results. Damaged or partially covered QR codes may not scan.

Use Cases

  • Website links and landing pages
  • Wi-Fi sharing for guests
  • Product labels and packaging
  • Event check-in and tickets
  • Contact card sharing
  • Document and material sharing
  • Device identification tags
  • Product batch tracking
  • Promotional posters and flyers

Frequently Asked Questions

Do generated QR codes expire?▼
No. Static QR codes do not expire. The content is permanently encoded in the pattern. However, if the linked URL becomes invalid, the QR code will no longer lead to that page.
Is QR code content uploaded to a server?▼
No. All QR code generation is done in your browser. No content is sent to any server.
Can I modify a generated QR code?▼
No. Static QR codes cannot be modified after generation. If you need different content, generate a new QR code.
Why does my QR code fail to scan?▼
Common reasons: low color contrast, logo too large covering too much data, insufficient margin, stretched/distorted image, or complex style reducing readability. Try increasing error correction to H and using standard black and white colors.
Can I add a logo to the QR code?▼
Yes. Upload a PNG, JPG, or WebP image as the logo. It will be placed in the center of the QR code. Use error correction level H for best results.
What is the ideal logo size?▼
The logo should not exceed 20% of the QR code area. The tool enforces a default limit of 18% to ensure reliable scanning.
What is the difference between L, M, Q, and H?▼
These are error correction levels. L recovers 7% of damaged data, M recovers 15%, Q recovers 25%, and H recovers 30%. Higher levels mean more redundancy but less data capacity.
How do I generate QR codes in batch?▼
Switch to the Batch tab. You can enter multiple lines of text, upload a CSV file, or use the serial number generator. Then download all QR codes as a ZIP file.
Is SVG supported?▼
Yes. You can download QR codes in PNG, SVG, and WebP formats. SVG is ideal for print and design software.
Why can't I scan the QR code after printing?▼
Print resolution, paper texture, and ink quality can affect scanning. Use high resolution (at least 1024x1024), ensure good contrast, and test print one copy before mass printing.
Does the Wi-Fi QR code expose my password?▼
The password is encoded in the QR code pattern. Anyone who scans it can see the password. This is inherent to Wi-Fi QR codes. Use for guest networks or share with trusted people.
Can QR codes track scan counts?▼
Static QR codes cannot track scans. This tool generates static QR codes only. For scan analytics, you would need a dynamic QR code service with a redirect server.

QR codes and logos are processed in your browser. Nothing is uploaded to Qudo servers.