Generate QR Codes — No Tracking, No Server
QR codes (Quick Response codes) are 2D barcodes that any smartphone camera can read. They're used everywhere: restaurant menus, business cards, event tickets, product packaging, and digital-to-physical marketing bridges.
Cluster Tools generates QR codes using the qrcode.js library running directly in your browser. The data you encode (your URL, email address, WiFi credentials, etc.) is never sent to a server. This matters particularly for sensitive uses like WiFi passwords or private contact information.
Many "free" QR code generators are actually monetization tools: they redirect through their own server so they can track how many times your QR code was scanned, then upsell you to a paid plan to see the analytics. Cluster Tools generates static QR codes that link directly to your destination — no server in the middle, no scan tracking, no subscription required.
What You Can Encode in a QR Code
URLs — the most common use. Encode any web address, from simple URLs to complex ones with query parameters. The QR code becomes a bridge from print to web.
Plain text — encode a note, an address, a product serial number, or any text up to about 4,000 characters (capacity decreases as you add more error correction).
Email addresses — encode a mailto: link that opens the user's email app pre-addressed when scanned.
Phone numbers — encode a tel: number that dials when scanned on a mobile device. Common for business cards.
SMS messages — encode an sms: URI that opens the messaging app with a pre-filled number and message.
WiFi credentials — encode SSID, password, and security type (WPA2/WPA3) in the format WIFI:T:WPA;S:MyNetwork;P:MyPassword;;. Most modern phones auto-connect to the WiFi when the QR code is scanned — no typing required.
VCard contacts — encode a complete contact card (name, phone, email, address) in vCard format. When scanned, the user can save the contact directly to their phone.
Geographic coordinates — encode a geo: URI to open the user's maps app pointing to a specific location.
QR Code Error Correction Levels
QR codes have built-in redundancy that allows them to be read even when partially damaged or obscured. Four error correction levels:
| Level | Recovery Capability | Use Case | |---|---|---| | L (Low) | 7% data recovery | Maximum capacity, ideal conditions | | M (Medium) | 15% data recovery | Default — good balance | | Q (Quartile) | 25% data recovery | Outdoor printing, some damage expected | | H (High) | 30% data recovery | Logos overlaid on QR code, rough conditions |
Higher error correction = more redundancy = more complex QR code = smaller data capacity. For most URL QR codes, level M is ideal. If you're embedding a logo in the center of the QR code, use level H.
Step-by-Step: How to Generate
- Select content type — URL, text, email, phone, WiFi, etc.
- Enter your data — the QR code preview updates in real time.
- Adjust settings — error correction level, size (pixels), foreground/background colors.
- Download — choose PNG for raster output (printing, digital) or SVG for scalable, print-ready vector output.
Tips for Using QR Codes Effectively
Test before printing — always scan your generated QR code with at least two different phones before printing thousands of flyers.
Size matters — the minimum recommended print size is 2cm × 2cm for a QR code that will be scanned at arm's length. For wall posters or signage scanned from a distance, scale up proportionally.
Contrast is critical — high contrast between foreground (default: black) and background (default: white) is essential for reliable scanning. Avoid pastel foregrounds or tinted backgrounds.
Short URLs scan faster — less data = less complex QR = faster scan. If your URL is very long (especially with UTM parameters), use a URL shortener first.
Frequently Asked Questions
Will my QR code stop working if Cluster Tools goes down? No. The QR codes Cluster Tools generates are static — they encode data directly. If you encoded a URL, the code links directly to that URL. There's no Cluster Tools server involved in the redirect.
Can I add a logo to the center of the QR code? Download the SVG or PNG and overlay your logo in a design tool. Use error correction level H when generating, as the logo will cover part of the code.
Do QR codes expire? Static QR codes (like the ones Cluster Tools generates) never expire. They encode data directly. Only "dynamic" QR codes from tracking services expire if you stop paying.
What's the maximum amount of data I can encode? ~4,296 alphanumeric characters (lower with binary data). In practice, QR codes work best with under 300 characters — longer data results in a very dense, harder-to-scan code.
Related Tools
- Slug Generator — create clean URLs to encode in your QR codes.
- URL Encoder/Decoder — encode URLs with special characters before creating QR codes.
- Meta Tag Generator — ensure the landing page your QR code points to is well-optimized.