Crypto glossary
Crypto QR code
A crypto QR code encodes a wallet address or full payment request, with amount and network, so a phone wallet can scan it instead of copying long strings.
Typing a 40-character address by hand invites mistakes, so wallets turn it into a QR code. The simplest code contains only the address. Richer ones follow payment URI standards, such as BIP 21 on Bitcoin, which adds amount and label, or EIP-681 on Ethereum, which can specify the token and chain. Lightning invoices are also shared as QR codes and include the amount and an expiry time.
QR codes are how crypto works at a point of sale: the merchant's terminal displays a code, the customer scans it, checks the amount and confirms. They are also the bridge between devices, letting a phone wallet pay from a code on a laptop screen or an air-gapped signer exchange data with a companion app.
The code itself carries no trust. Scammers place stickers over genuine codes on posters and parking meters, send QR codes in phishing emails, or display them on fake support sites. Some codes point to a website rather than an address and lead to a drainer. After scanning, compare the first and last characters of the address and the network before confirming.
Example
At a café that accepts bitcoin, the till shows a Lightning invoice as a QR code; the customer scans it, sees the amount in sats and pays in a couple of seconds.