What Can an Online QR Code Generator Do?
A QR Code is a matrix-type two-dimensional barcode that can store a large amount of information and be quickly scanned and recognized by mobile phones. Our online QR code generator runs entirely in your browser, supporting the conversion of text, URLs, WiFi configurations, electronic business cards (vCard), and more into standard QR code images. You can customize the appearance, embed a brand logo, and batch generate high-resolution PNG/SVG files.
Unlike most online QR code tools on the market, we never upload your data to any server. All QR code encoding is performed on your device, so it works even without an internet connection. This is especially important for QR codes containing sensitive information (such as WiFi passwords or internal system links).
Supported QR Code Content Formats
- Plain Text/URL: Directly enter a URL or text content; scanning gives access or displays the content
- WiFi Auto-Connect: Format
WIFI:T:WPA;S:NetworkName;P:Password;;, scanning automatically connects to WiFi
- Electronic Business Card (vCard/MECARD): Format
MECARD:N:Name;TEL:Phone;EMAIL:Email;;
- Phone Number: Format
TEL:+15551234567, scanning directly dials the number
- Email Address: Format
MATMSG:TO:email@example.com;SUB:Subject;BODY:Body;;
- Geographic Location: Format
geo:latitude,longitude
How to Choose a QR Code Error Correction Level?
QR codes have a built-in Reed-Solomon error correction algorithm, so even if the QR code is partially damaged or smudged, it can still be decoded correctly. The higher the error correction level, the more data can be recovered, but the QR code pattern also becomes more complex (more modules).
- Level L (~7%): Suitable for clean environments, smaller sizes, and simple content
- Level M (~15%): The recommended default option, balancing error tolerance and complexity
- Level Q (~25%): Suitable for scenarios requiring logo embedding or use in harsh environments
- Level H (~30%): Highest error tolerance, suitable for scenarios with large-area occlusion or severe smudging, but results in the largest QR code size
If you plan to embed a logo in the center of the QR code, it is recommended to choose at least Level M or higher. The logo will occlude some data modules, and sufficient error correction redundancy ensures a high scanning success rate.
How to Generate a QR Code with a Logo?
Branded QR codes are an important tool in modern marketing. This tool supports uploading logo images in PNG/JPG/WebP format, which are automatically centered and overlaid on the QR code. To ensure scanning success, it is recommended to:
- Keep the logo size within 15-20% of the total QR code area
- Choose Level M or higher error correction
- Use a transparent or light-colored logo background to avoid dark edge interference
- Test the scanning effect with multiple phones after generation
Frequently Asked Questions (FAQ)
Is the QR code data uploaded to a server?
No. This tool is implemented with pure frontend technology, and all QR code encoding is performed in your browser. You can press F12 to open the developer tools and check the Network panel to confirm that no data upload requests are made. The tool works normally even when offline.
Why can't some QR codes be scanned?
Common reasons include: ① The QR code size is too small or print resolution is insufficient; ② The contrast between foreground and background colors is too low (e.g., light gray on white); ③ The embedded logo is too large and covers key areas; ④ The input content is too long, making the QR code too dense. It is recommended to use black-and-white or high-contrast color schemes and keep the printed size no smaller than 2cm×2cm.
How much data can a QR code store?
QR codes support 40 versions (Version 1-40); higher versions have larger capacity. In Byte mode (UTF-8), Version 40 can store up to approximately 2953 bytes (about 1000 Chinese characters or 3000 English letters). This tool automatically selects the smallest usable version based on content length.
What's the difference between SVG and PNG downloads?
PNG is a bitmap format, suitable for direct use on web pages, social media, email, and similar scenarios. SVG is a vector format that can be scaled infinitely without blurring, making it ideal for printing (posters, flyers, product packaging) or design scenarios requiring later editing. For printing, use SVG; for screen display, use PNG.
How many QR codes can be generated at once in batch mode?
The batch generation feature has no hard limit, but due to browser performance constraints, it is recommended to generate no more than 50 at a time. Enter one independent item per line, and the system will generate a QR code for each line and display it below. You can download each QR code individually, or click "Download All" to save all PNG images at once.
Do WiFi QR codes work on both iPhone and Android?
iPhone (iOS 11+) native Camera app can directly recognize WiFi QR codes and prompt to connect. Android support varies by manufacturer: Google Pixel and some Android systems (Xiaomi, Huawei, OPPO, etc. in newer versions) support WiFi auto-connect via the camera or system scanner. If the system doesn't support it, users can use a third-party scanning app to read the password and enter it manually.