Crypto address checker: which network is this wallet address on?

No, and neither can anything else, because the address does not carry that information. An Ethereum-style address is a 20-byte key, and the same key is valid on Ethereum, BNB Smart Chain, Polygon, Arbitrum, Optimism, Base, Avalanche and every other EVM chain at once. The checker tells you the address belongs to that family; which chain the recipient expects is something only the recipient knows. On an exchange withdrawal screen, the list of networks offered for a pasted address is the list the exchange can send on, not the list the destination will credit - so read the recipient's deposit page, not the sender's menu.

It depends on which mistake you made. A TRON address and an Ethereum address are different formats, so a wallet or exchange refuses that combination outright and nothing is sent. The dangerous case is two networks that share a format: USDT sent on BNB Smart Chain to a 0x address whose owner expected Ethereum lands at that address on BNB Smart Chain. If the owner controls the private key, they switch network in their wallet and the tokens are there. If the address belongs to an exchange, the tokens sit in an account the exchange did not expect them in; recovery is a support ticket, often a fee, and sometimes a refusal. That is the whole reason to check the network before sending rather than after.

A receiving address is public by design - it is the thing you hand out so that people can pay you - so pasting one reveals nothing that the blockchain does not already show. Beyond that, the check runs entirely inside your browser tab: the address is not sent to our server, not stored, and not included in any analytics event (the only event records which network family was detected, never the string). What you should never paste into any website is a seed phrase or a private key; the checker recognises both and warns you, but by then the words have been typed, so treat them as exposed.

No. A passing checksum means the address is spelled correctly - every character is what its author wrote. It says nothing about who that author is. The common attack that exploits this is address poisoning: someone sends a tiny transfer from an address whose first and last characters match a real contact of yours, hoping you copy it from your transaction history next time. That poisoned address has a perfect checksum. Copy addresses from the recipient's own message or wallet, never from a history list, and compare more than the first and last four characters.

On XRP, Stellar, TON, the Cosmos chains, Hedera and a few others, an exchange does not give each customer a separate deposit address. Every customer shares one address, and a second field - the destination tag on XRP, the memo elsewhere - says which account the deposit belongs to. If the recipient is an exchange, it shows you both values and you must enter both; send the address alone and the coins arrive at the exchange with nothing to say they are yours, which means a support ticket. If the recipient is a personal wallet, the address alone identifies it and no tag is needed. The checker flags the networks where the question arises.

Because a token like USDT is issued on many networks at once - TRON, Ethereum, BNB Smart Chain, Solana, TON, Polygon, Arbitrum and more - and each copy is a separate asset with its own fee. The withdrawal screen lists every network the exchange can send on, and the fees differ by a factor of a hundred or more between them. The address format narrows the choice to a family (a T… address can only be TRON, a 0x address can be any EVM chain), and within that family the sender picks. Cheapest is not automatically right: the destination has to credit deposits on that network too.

No, on purpose - looking up a balance means sending the address to a server, and this page sends nothing. What it does instead is hand you to a public block explorer for the detected network, where balances and history are public for anyone to see (Monero is the exception: its balances are private by design and no explorer can show them). Risk scoring of an address against sanctions and hack lists is a separate kind of service, run by compliance providers, and is not what this checker does.