Guides / Troubleshooting
Troubleshooting QR codes and barcodes
These checks use the messages and payload rules in this app. They are not a report of a phone or scanner test.
URL preview added https://
On the QR generator, type qrbarcodetool.com/guides with URL selected. The payload becomes https://qrbarcodetool.com/guides. Leave the field empty and Download stays disabled.
Wi-Fi password contains a semicolon
On Wi-Fi QR, SSID CafeGuest, encryption WPA, password a;b, hidden off. The payload is WIFI:T:WPA;S:CafeGuest;P:a\;b;H:false;;. Choosing None drops the P: field.
EAN-13 or UPC-A says Invalid checksum
On the barcode generator, EAN-13 with 12 digits appends a check digit and allows download. Thirteen digits with a wrong last number show Invalid checksum. Expected N, where N is the digit this page calculated. UPC-A does the same for 11 or 12 digits. 036000291452 passes the UPC-A check in this code. A blank Code 128 value shows Enter a value to encode.
Contrast and margin controls
The customise panel sets foreground, background, and margin before download. The QR margin slider runs from 0 to 4 modules. This page does not claim a minimum print size that was measured on a device.
Related reading: QR types, barcode formats, use cases.
Not added yet. Add a photograph you took of a printed code, and a note of the phone or scanner you used. Do not publish a stock image or a result you did not record.