Online 查U is a free blockchain data service focused on looking up and monitoring USDT addresses on the TRON network. Its tools bring key account information together, including TRC20 USDT and TRX balances, other token assets, transfer histories, account permissions, and transaction statistics. Users can review incoming and outgoing transfers, track fund flows, and examine activity between two addresses. The service also offers address-clustering analysis to identify possible links between wallets, supporting routine checks, on-chain research, and risk assessment.

For ongoing monitoring, users can set balance-change alerts and receive real-time notifications through a Telegram bot after registering, signing in, and linking an account. Online 查U states that it queries public blockchain data and does not request private keys or recovery phrases. It presents itself as a secure, efficient, and straightforward tool, with a compact interface designed for both mobile and desktop use. The service is intended for TRON addresses, which begin with “T,” and provides a convenient way to check balances, confirm transfers, and follow address activity.