Which codes this scanner reads
The scanner is built on the ZXing format set, so it is not limited to QR codes. In practice it reads:
- Two-dimensional: QR Code, Data Matrix, Aztec, PDF417. These hold text, so they can carry a link, a Wi-Fi network, a contact card or a payment string.
- Retail: EAN-13, EAN-8, UPC-A, UPC-E. These hold a product number and nothing else — scanning one gives you digits, not a product name, because the name lives in a shop's database rather than in the code.
- Logistics and industrial: Code 128, Code 39, Code 93, ITF, Codabar, GS1 DataBar.
If you have a picture of a code rather than the code itself, use scan from image instead — it runs the same decoder on a file you upload.
If the camera does not start
Almost every failure here is a permission, not a fault in the page.
- The prompt appeared and you dismissed it. Browsers remember that answer. Click the padlock or camera icon at the left of the address bar, set Camera back to Allow or Ask, and reload the page.
- You are inside another app's browser. Links opened from a chat or social app often run in a stripped-down in-app browser that is not given camera access. Use the menu to open the page in Safari or Chrome itself.
- Something else is holding the camera. A video call in another tab or app will keep it. Close that first.
- The page must be on HTTPS. Browsers only hand the camera to a secure origin. This site is HTTPS everywhere, so a plain http:// address is a redirect, never the page you end up on.
- No camera at all. On a desktop without a webcam, use Upload image and photograph the code with your phone first.
Why a code will not scan
When the camera is running but nothing is detected, it is nearly always one of these:
- Distance. About 10–20 cm for a phone. Closer than that and the lens cannot focus; much further and a small code stops resolving.
- Focus. Tap the preview to force a refocus. A blurred code is the single most common cause.
- Glare. Glossy paper, laminated menus and screens all reflect. Tilt the code slightly away from the light rather than moving the camera.
- Reading off a screen. Lower the brightness of the screen showing the code, not the one you are scanning with. A bright screen blows out the dark modules.
- The quiet zone is missing. Codes need a blank margin around them. One cropped flush to its edge, or pasted onto a dark background, often cannot be found at all.
- Inverted colours. A light code on a dark background is decodable in theory and refused by many scanners in practice.
- Low contrast. Red bars are effectively invisible to a red-light laser scanner, and pale colour-on-colour QR codes fail for the same reason. Dark on light wins.
- Damage or a logo covering too much. QR codes carry error correction and survive a surprising amount, but a barcode with a scuffed bar is simply gone.
Phone or laptop
A phone's rear camera has autofocus and is the right tool. A laptop webcam is usually fixed-focus and wide-angle, which is why a dense code held up to it stays stubbornly unread — the code occupies too few pixels and never comes into focus. On a laptop, photograph the code with your phone and use Upload image; a still photo is decoded from the full resolution of the file rather than from a small live preview.
Before you open a link you scanned
A QR code is only text. It cannot install anything by itself, and the code is never the danger — where it sends you is. This scanner shows you the decoded content first and never opens anything on its own, which is the point of reading it here rather than in a camera app that jumps straight to the page.
- Read the whole address, and read the domain. The last part before the first single slash is what matters. Reassuring words earlier in the address mean nothing.
- Be wary of a sticker. Codes on parking meters, restaurant tables, posters and delivery notices are a known target: a fake sticker goes over the real code and nothing looks wrong.
- Shortened links hide the destination. If a printed code resolves to a shortener, you cannot see where it goes until you are already there.
- Never enter a password or card detail on a page you reached only by scanning. If a code leads to a login or a payment form, stop, and reach that service the way you normally would.
What happens to what you scan
Camera frames are decoded inside your browser and are never uploaded; no image or video leaves your device. Results are saved to your history using your browser's own storage on this device, which also means clearing your browser data erases it permanently — there is no copy anywhere else, including with us. Our privacy policy sets out the rest.