Solana: wallet or PDA?
A Solana address is 32 bytes. If they decode to a point on the Ed25519 curve, a private key can sign for it — a wallet. If not, it is a program-derived address that only a program controls.
Why it matters
Token accounts and program vaults live at off-curve addresses. Sending SOL or tokens directly to one may leave them where no wallet can move them. Exchanges and wallets give on-curve addresses for deposits. Solana addresses have no checksum, so the test says nothing about typos.
A valid format does not mean the address belongs to the right person. It only means the address is well-formed. Compare the whole address with the source and send a small test amount first.
FAQ
What does “on curve” mean for a Solana address?
The 32 bytes are a valid Ed25519 public key, so a private key exists for it. Wallet addresses are on the curve.
What is a PDA?
A program-derived address: deliberately off the curve, so no private key exists and only the program that derived it can authorise transfers.