What this QR code generator actually creates
The tool creates a standard QR Code Model 2 symbol from the exact payload shown beside the preview. It uses byte mode with UTF-8 encoding, automatically selects the smallest version that can hold the data at the chosen correction level, and keeps a clear border around the symbol. The encoder is self-hosted with this page, so an external QR service does not receive your URL, Wi-Fi password or contact card.
Templates are payload builders, not magic actions. URL mode creates an HTTP or HTTPS link. Wi-Fi mode uses the widely implemented ZXing WIFI: convention. Contact mode creates vCard 3.0 text; email and phone modes use mailto: and tel:. What happens after scanning depends on the camera app, operating system, security policy and installed apps.
Version, capacity and why a code becomes denser
DENSO WAVE defines QR Code versions 1 through 40. Version 1 is 21 × 21 modules; each later version adds four modules per side, reaching 177 × 177 at version 40. Capacity depends on the data mode and correction level, not character count alone. A Chinese character or emoji uses multiple UTF-8 bytes, while a long URL can also expand quickly because tracking parameters are encoded literally.
The diagnostic panel reports UTF-8 bytes, chosen version and module count after a successful build. If the encoder reports overflow, shorten the payload, remove unnecessary URL parameters or reduce the correction level. A short redirect can make a simpler code, but it also creates a dependency: if the redirect stops working or changes ownership, the printed QR code changes destination without changing appearance.
Error correction is a capacity trade-off
The four levels are L, M, Q and H. DENSO WAVE lists approximate restoration capability of 7%, 15%, 25% and 30% respectively and notes that M is the most frequently selected level. Restoration is not a promise that any damaged code will scan; the position, pattern and printing damage matter. Higher correction stores more redundancy, leaving less room for payload data and often selecting a larger version.
| Level | Approx. restoration | Practical starting point |
|---|---|---|
| L | 7% | Clean digital display, capacity-sensitive payload |
| M | 15% | General-purpose default |
| Q | 25% | Labels or surfaces with modest wear risk |
| H | 30% | Higher damage risk when the denser result still scans |
Quiet zone, color and export quality
DENSO WAVE specifies a four-module-wide quiet zone on every side of a standard QR Code. This generator enforces four as the minimum and includes it in both exports. Do not crop that border or place text, logos, frames or patterns inside it. Choose dark modules on a light background and keep strong contrast; decorative gradients, transparency and inverted colors can reduce compatibility even when one phone scans the preview.
SVG is the better master file for print because it stays sharp at different sizes. PNG is convenient for social posts, office documents and systems that reject SVG. Do not stretch a PNG to a non-square shape or resample it with blur. Always test the final artifact—not only the browser preview—at the actual viewing distance, on multiple devices, before printing a large batch.
Wi-Fi QR safety and escaping
A Wi-Fi QR code contains the network name, security type and usually the password in readable text. It is convenient for a guest network, but it is not a substitute for access control. Anyone who photographs or scans the code can retain the credentials. Prefer a separate guest network, rotate the password when the audience changes, and avoid publishing a code for a private administrative network.
The ZXing payload convention reserves backslash, semicolon, comma, double quote and colon in Wi-Fi fields. The builder escapes those characters before showing the final payload. Some older scanners may not understand newer security combinations or hidden networks, so keep a manual connection fallback.
Inspect links before opening them
A QR image hides its destination from casual sight. The U.S. Federal Trade Commission warns that scammers can replace real codes or use them to send people to look-alike sites. Use a scanner that previews the destination, check the hostname and HTTPS connection, and do not enter credentials or payment information after an unexpected scan. When publishing a code, print the human-readable domain beside it so people have something to compare.
Implementation notes and primary references
- DENSO WAVE: QR Code versions and module dimensions
- DENSO WAVE: error correction levels and trade-offs
- DENSO WAVE: four-module quiet zone
- ZXing project: URL, Wi-Fi, email, phone and vCard payload conventions
- U.S. FTC: recognizing malicious QR links
- Kazuhiko Arase QR encoder source (MIT license)
Editorial and implementation review: 2026-08-02. Payload construction, reserved-character escaping, UTF-8 encoding, capacity failure, quiet-zone output and page integration are covered by deterministic tests. “QR Code” is a registered trademark of DENSO WAVE INCORPORATED.
Frequently asked questions
Does this QR code generator upload my content?
No. The encoder, preview and SVG/PNG export run in your browser. The tool does not put content in the page URL or send it to an EasyTool API. Browser extensions, your device and the destination you encode remain outside that boundary.
Which error correction level should I use?
M is a sensible general default. DENSO WAVE describes approximate restoration of 7% for L, 15% for M, 25% for Q and 30% for H. Higher correction uses more capacity and can make the symbol larger.
Why does my QR code fail to scan?
Keep a clear quiet zone of at least four modules, use dark modules on a light background, avoid resizing blur, do not crop the edges and test the final printed or displayed code on more than one scanner.
Can I make Wi-Fi and contact QR codes?
Yes. Wi-Fi mode builds the common ZXing WIFI payload and escapes reserved characters. Contact mode creates a vCard 3.0 payload. The exact action still depends on the scanner and operating system.
Should I use SVG or PNG?
Use SVG for print, signage and layouts that may be resized. Use PNG when an app requires a raster image. Both exports include the selected quiet zone.