How QR Codes Work
A QR (Quick Response) code stores data as a grid of black and white squares that any smartphone camera can read in an instant. Unlike a barcode, which only holds a small number along one axis, a QR code stores data in two dimensions, which is why it can hold URLs, contact cards, WiFi credentials, and long text strings.
This tool generates every QR code locally in your browser using the industry-standard Reed-Solomon error correction algorithm. Nothing you type is sent to any server.
Choosing the Right Content Type
| Type | Best For | Example Content |
|---|---|---|
| Text / URL | Links, plain text, any custom string | https://tooltri.com |
| WiFi | Sharing network access without typing a password | SSID, password, WPA2 |
| Contact | Sharing your phone number and email as a vCard | Name, phone, email |
| Pre-filling a compose window with recipient and subject | to, subject, body |
Error Correction Explained
QR codes are built to survive real-world conditions: smudges, folds, partial shadows, and low-quality prints. Error correction adds redundant data so a scanner can reconstruct the original content even when part of the code is missing.
- Low (L): Smallest code, least redundancy. Good for clean digital displays only.
- Medium (M): The default. Suitable for most uses including websites and documents.
- Quartile (Q): Recommended for printed materials that may get worn or partially obscured.
- High (H): Maximum redundancy. Use this for outdoor signage, packaging, or anywhere the code will face wear and tear.
Higher error correction levels produce more complex (denser) codes, which require a larger physical print size or a higher-resolution image for reliable scanning.
PNG vs. SVG: Which Format to Use
PNG is a pixel-based image. The quality is fixed at the size you choose (256px, 512px, or 1024px). It works in every app, email client, and document editor without any special support.
SVG is a vector format. The file describes the code as mathematical shapes rather than pixels, which means it can be scaled to any size (a business card or a billboard) with perfect clarity and no blurriness. Use SVG for professional print work or anywhere you need to resize the image.
Tips for a Scannable QR Code
- Keep enough contrast between the foreground (dark) and background (light) colors. Avoid pastels, gradients, or low-contrast combinations.
- Leave a quiet zone (white border) around the code. Most scanning apps require at least a small margin to locate the code boundary.
- Longer content creates a denser, harder-to-scan code. For URLs, use a short-link service to reduce the payload if the code looks very complex.
- Test your code with at least two different scanning apps before printing or distributing it.