How to Send Crypto Using a QR Code in MetaMask?

QR Code Scanning Fundamentals

1. MetaMask supports QR code scanning exclusively through its mobile application, not the browser extension version.

2. The scanner is built into the wallet interface and requires camera permissions to function properly.

3. Scanned QR codes must encode a valid EVM-compatible address or payment request URI with correct checksum formatting.

4. Addresses encoded in QR format follow the Ethereum Address Checksum standard (EIP-55), ensuring case-sensitive validation before transaction submission.

5. Unsupported QR formats—such as those containing malformed hex strings or non-EVM chain identifiers—trigger immediate rejection without confirmation prompts.

Step-by-Step Transaction Initiation

1. Open the MetaMask mobile app and ensure you are on the correct network tab—Ethereum Mainnet, Sepolia, or another configured EVM chain.

2. Tap the “Send” button located at the bottom navigation bar.

3. In the recipient field, tap the camera icon positioned to the right of the input box.

4. Align the QR code within the frame; the app automatically detects and decodes it upon successful focus.

5. After decoding, the recipient address appears pre-filled and is displayed with full 40-character hexadecimal representation for manual verification.

Security Validation Layers

1. MetaMask performs real-time checksum validation against the decoded address using keccak256 hash comparison.

2. If the QR contains an embedded amount or token symbol, the app cross-references it with the currently selected asset in the wallet balance panel.

3. Any mismatch between embedded parameters and active network settings halts the flow and displays a red warning banner.

4. The app disables the “Confirm” button until the user manually taps “Next” after reviewing all fields—even if the QR includes complete transaction metadata.

5. A secondary visual indicator—a green checkmark beside the address—only appears after both checksum validation and network compatibility pass.

Common Encoding Standards

1. Standard Ethereum address QRs contain only the 0x-prefixed 40-character string, e.g., 0x742d35Cc6634C0532925a3b844Bc454e4438f44e.

2. Payment request URIs use the ethereum: scheme followed by the address, optional ?value parameter in wei, and ?gas parameter if specified.

3. Multi-chain QRs embed chain ID via the ?chainId= parameter; MetaMask rejects any chain ID not present in its internal network registry.

4. ERC-20 token transfers require full contract address inclusion in the URI, otherwise the scanner treats the payload as ETH-only.

5. QR codes generated from hardware wallets or third-party dApps must include the ?label= parameter to display sender identification in the transaction preview screen.

Frequently Asked Questions

Q: Can I scan a QR code that contains a BSC or Polygon address using MetaMask Mobile?A: Yes—if the target network is already added to your wallet and actively selected. Scanning a BSC address while on Ethereum Mainnet triggers automatic network switch confirmation.

Q: Why does MetaMask show “Invalid QR code” even when the address looks correct?A: Most often due to missing 0x prefix, incorrect capitalization violating EIP-55, or invisible Unicode characters embedded during QR generation.

Q: Does MetaMask store or transmit scanned QR data to external servers?A: No. All decoding occurs locally on-device. Camera feed and decoded payloads never leave the device memory.

Q: Can I generate a QR code from my MetaMask address to share with others?A: Yes. Tap your account avatar → “Account Details” → “Share Address”. This generates a scannable QR containing only your public address—not private keys or recovery phrases.