ISO/IEC 18004 QR Code Encoding & Client-Side Decoding
This utility implements Reed-Solomon error correction over GF(256) directly in JavaScript to encode URLs, plain text, Wi-Fi network credentials, and vCard contacts at L (7%), M (15%), Q (25%), and H (30%) recovery levels, and decodes QR matrices locally in your browser without uploading sensitive images to any server.
Reed-Solomon Error Correction
Select from four ISO/IEC 18004 error correction levels—Level L (~7%), Level M (~15%), Level Q (~25%), or Level H (~30%)—balancing symbol density against physical damage resilience.
Wi-Fi & vCard Payload Builders
Automatically formats standard WIFI:T:WPA;S:...;P:...;; provisioning strings and BEGIN:VCARD contact payloads so mobile cameras trigger native Wi-Fi join or contact save prompts.
Offline Image & Canvas Decoder
Drop a screenshot or photo of a QR code to extract its raw payload locally using HTML5 Canvas pixel sampling and the browser's BarcodeDetector / matrix decoder pipeline.
Frequently Asked Questions
Which QR Error Correction Level (ECC) should I use?
Level M (15%) is the standard default for screens and printed labels. Choose Level Q (25%) or Level H (30%) if the QR code will be printed outdoors or may be partially smudged or obscured.
Are uploaded QR images or Wi-Fi passwords sent to a backend server?
No. Both QR matrix rendering and image decoding happen 100% locally inside your browser's JavaScript runtime and HTML5 <canvas> element.