What Is a QR Code?
A QR code is a two-dimensional barcode that encodes data in a grid of black and white modules, defined by the international standard ISO/IEC 18004. As a qr code generator free of watermarks, scan limits, or expiry, this tool works as a qr code maker to generate qr code images for a URL, plain text, email, phone number, SMS message, WiFi network, or vCard contact instantly. Every content type uses the correct underlying payload format, not just plain text, so scanning apps interpret it properly: a wifi qr code generator output actually offers to auto-join the network, and a vCard output actually offers to save the contact, rather than just displaying raw text on scan.
QR Code Error Correction Levels (L, M, Q, H)
Every QR code encodes redundant data using Reed-Solomon error correction, so it keeps scanning even if part of it is damaged, dirty, or covered by a logo. The qr code error correction level determines how much of that damage it can tolerate: L recovers from about 7% data loss, M about 15%, Q about 25%, and H about 30%. Higher error correction means more redundant data, which means a larger, denser code for the same content, a real tradeoff rather than a free upgrade with no cost.
| Level | Approximate recovery | Best for |
|---|---|---|
| L | ~7% | Clean digital display, smallest code, maximum data capacity |
| M | ~15% | General-purpose use, the common default |
| Q | ~25% | Printed material handled physically, moderate wear expected |
| H | ~30% | Small prints, logo overlays, or codes exposed to damage |
WiFi, vCard, Email, and SMS QR Code Formats Explained
A WiFi QR code is not just the network name and password as plain text; it is a specific structured payload, WIFI:T:<security>;S:<ssid>;P:<password>;H:<hidden>;;, that WiFi-aware scanning apps parse and offer to auto-join. The vcard qr code format embeds an RFC 6350-style block (BEGIN:VCARD ... END:VCARD) that phone contact apps recognize and offer to save directly as a new contact. Email, phone, and SMS types use the mailto:, tel:, and sms: URI schemes respectively, the same schemes a phone dialer or mail app already understands from a tapped link. Selecting the correct content type in this tool, not the generic text type, is what makes the resulting code trigger the right app behavior on scan.
QR Code Size Limits and Version
The qr code size limit characters question comes up constantly, and it comes from the ISO/IEC 18004 standard's defined versions, numbered 1 through 40, each specifying a module grid size and maximum data capacity. The encoder automatically picks the smallest version that fits the content at the chosen error correction level, which is why a full vCard produces a visibly larger, denser code than a short URL. At the largest standard version, capacity tops out around a few thousand alphanumeric characters; content beyond that either fails to encode or produces an impractically dense code.
What This Tool Does Not Do
This tool generates standard QR codes, not Micro QR codes, a smaller variant meant for very short data on space-constrained labels. It also can't diagnose qr code not scanning why issues in a code generated elsewhere; troubleshooting a third-party code's contrast, margin, or error correction requires regenerating it here to compare. It does not vet the safety of encoded content: a URL you enter here is exactly as trustworthy as the URL itself, and scanning any QR code, including ones from unfamiliar sources, carries the same risk as clicking an unfamiliar link. Nothing you enter, a WiFi password or contact details included, is uploaded; the code is generated entirely client-side.