- Which image formats and sizes can I upload?
- The decoder accepts PNG, JPG/JPEG, GIF (first frame), WebP, and BMP files up to about 10 MB. Images up to roughly 4,096 px on the longest edge work best. For printed posters or screenshots, crop the QR region first to improve detection speed.
- Why does decoding fail or return empty data?
- Most failures are caused by blurry photos, low contrast, reflective surfaces, or QR corners being cut off. Make sure the finder patterns (three squares) are visible, avoid motion blur, and try increasing lighting. If the QR uses micro/circular style modules, toggle the high-contrast filter and re-upload.
- Can I decode multiple QR codes in one image?
- Yes. The detector scans the whole canvas, isolates each QR, and lists every result. If codes overlap, crop them individually for higher accuracy. You can also drag several files into the drop zone to batch-decode one after another.
- What types of payloads does the decoder recognize?
- Plain text, URLs, mailto:/tel:/sms: links, WiFi credentials (WIFI:T:;S:;P: format), vCard / MeCard contacts, calendar events, payment and crypto URIs, and custom application schemes. The tool shows both the raw string and a structured summary when possible.
- Is my image uploaded or stored anywhere?
- No. All image processing, barcode detection, and decoding run entirely in your browser using WebAssembly and Canvas APIs. Files never leave your device and are cleared from memory as soon as you close or refresh the page.
